iOS virtual instrument apps roundup

PrintIf you have subscribed to the Music App Blog email newsletter then you will have obtained a copy of our free guide titled ’25 iOS music apps to get you started’. This guide is now in its second edition (I updated it in May 2014) but, as keen eyed readers will have noted (err….  or anyone who can actually count) there are actually rather more than 25 apps listed in the guide.

The reason for this is (a) quite simple and (b) rather wonderful. It’s simple because the iTunes App Store has a massive selection of iOS music apps available and wonderful because, from that massive selection, there is actually a very significant crop of really (really, really!) very good pieces of music software to be found.

So, the ’25 apps guide’ was a great way to get you started and, while it is most definitely a personal selection on my part (and your needs and choices may differ), you can think of it as a ‘best of the best’ list. What this means, of course, is that there are also a lot of very good music apps that did not make it into the guide….

guitar from computer

For the computer-based musician, virtual instruments are now an everyday tool for music creation.

OK, what about the rest of those apps? Well, if I was to do single post covering the ‘best of the rest’ then it would be loooonnnngggg (I know, I’ve never been shy of long posts but even I draw a limit somewhere). Instead, what I thought I’d do is split that potentially ‘mega-long’ post into a series of shorter app roundups….   and, in each post, taking a different category of app.

I’ve actually done a couple of these in the past looking at iOS DAW apps and guitar amp sim apps. However, as the title above suggests, this particular post with cover the category of ‘virtual instrument apps’. Other posts in the series will deal with effects apps, synth apps, MIDI performance apps, drum and groove box apps and ‘all-in-one’ electronic music production apps.

In each case I’ll try to wiz through my own selection of the main contenders in each category and give a flavour of what each has to offer. I can’t promise the lists will be exhaustive but, if you are looking to flesh out your own music app collection, it should give you a few useful pointers to get you started.

Virtual instruments as apps

If you have been around computer-based music (iOS or otherwise) for any length of time then you will be familiar with the idea of a ‘virtual’ instrument. However, if you are new to music technology and iOS represents your first exploration into music creation using a computing device, then a little background might be useful.

In essence, a ‘virtual’ instrument refers to the recreation of a ‘real’ instrument (a guitar, a drum kit, a piano, a violin, etc.) in software. This can actually take a number of forms, two of which are most common. First (and perhaps less common for most of the instruments just listed), software can actually model the fundamental physics that underlies the way the instrument creates sound. So, for example, this would involve modelling the way a string vibrates on an acoustic guitar and how that vibration triggers resonance in the guitar’s body. This is a hugely complex process and, even if you can construct a suitably realistic model, the odds are that it would take a pretty hefty computer system to run it. Incidentally, the one common exception to this is ‘modelled’ versions of hardware synths and I’ll deal with this situation in a separate ‘iOS synths roundup’ article.

The second form is based upon audio samples. In this case, the sound of the real instrument is recorded as audio and then, when you want to play the ‘virtual’ version, you trigger that audio sample to play back (and the most common way to trigger these sampled instruments is from a MIDI keyboard although there are other options). Of course, in practice, it requires something a bit more sophisticated than that. For example, let’s consider a piano….

While the human voice has been attempted as a virtual instrument (check out Vocaloid for the desktop), it is perhaps the one exception where virtual instruments can't deliver 'real' sound ing results if used with a bit if care.

While the human voice has been attempted as a virtual instrument (check out Vocaloid for the desktop), it is perhaps the one exception where virtual instruments can’t deliver ‘real’ sound ing results if used with a bit if care.

In order that the virtual version sounds at least a bit realistic, you need to sample multiple notes from the full range of the piano keyboard (this might not be every note as software can pitch shift sample to fill in the gaps but, frankly, it’s better if it is every note). However, you can play sustained notes on a piano and you can also play short (staccato) notes (plus other performance styles) so, for additional realism, you need to have samples of both and the ‘virtual’ instrument needs to allow the performer to switch between them in a natural fashion as they play. Then, of course, the piano sounds different if you play it softly compared to when you give the notes a good wack….  so you need to sample each note at different playing strengths….

And we could go on…  detailing all the subtle variations that need to be captured in the initial sampling and then reproduced by the sample playback engine when the performer tries to play the virtual instrument via their MIDI keyboard (or other MIDI triggering device). The bottom line here is that sample-based virtual instrument can also be complex (although generally not as complex as physically modelled versions of the same real instrument) and, for the best results, require very detailed sampling.

Virtual instruments on an iDevice?

In both these approaches to virtual instrument – physically modelled and sample-based – it is, therefore, quite easy to see why an iDevice might be at a bit of a disadvantage compared to your average desktop computer system. Even the latest iPads can’t really compete with a desktop system for CPU grunt (needed for the physical modelling approach) or RAM/hard drive storage (needed for the mega-sample sets).

In fact, given that most physically modelled virtual instruments focus on recreations of synths (including those that originally existed as analog hardware) as opposed to something infinitely more complex to model (for example, a violin), virtual synth apps can be created that run brilliantly on an iPad (even on earlier models of iPad). As I mentioned earlier, I’ll deal with these in a separate ‘iOS synths roundup’ post.

If you want a virtual piano to sound as good as a real piano then that requires a lot of detailed sampling.

If you want a virtual piano to sound as good as a real piano then that requires a lot of detailed sampling.

In terms of sample-based instruments there are perhaps more obvious limitations under iOS. The way this usually manifests itself is in reduced detail of the sampling that sits behind these app-based virtual instruments. First, this means fewer ‘performance articulations’ (for example, for a violin, you would have to load separate patches for performing notes played staccato, pizzicato, sustained, vibrato, etc. (on a desktop system, the better sampled instruments allow you to switch between these performance styles within a single patch).

Second, there tends to be fewer sample layers meaning you don’t get the sense of ‘expression’ as you move from playing quiet notes to louder notes – you just get the same sample played quietly or loudly and it’s not the same thing.

All that said, app developers have still managed to create some very credible sample-based instruments for iOS musicians. They may not have all the subtlety that a top-of-the-line desktop sample-based virtual instrument can muster but then neither to they have a top-of-the-line price tag. And some of them can also bring something unique via the touchscreen interface.

So, with that pre-amble in place, and leaving aside the virtual synths and virtual drum apps (both of which I’ll deal with in separate posts), let’s take a look at some of the best sample-based virtual instruments currently (at the time of writing anyway) available for iOS….  There is still quite a selection to consider though so, for convenience, I’ll deal with them in a number of sub-categories.

All-round apps

Let’s start with a few all-rounders. These are apps that provide broad collections of sample-based instruments. These might include guitars, pianos, keyboards, strings, brass, ethnic, drums, percussion, sound FX and various others. Having at least one of these all-rounders to hand is never a bad idea as their give you a bread and butter sound palette that can serve a wide range of purposes.

SampleTank logoSampleTank

Some iOS musicians have a bit of a love/hate relationship with IK Multimedia particularly because of their use of pop-up ads that appear on start-up in many of their iOS music apps. These can, of course, be irritating but, providing you can just let these slide without getting too excited, IK Multimedia do make some very good apps. In terms of a generic sample-based virtual instrument, SampleTank is most definitely up there with the best currently available.

SampleTank provides a collection of sample-based virtual instruments that you can play using the onscreen keyboard or via MIDI sent from another app (for example, Cubasis) or an external MIDI keyboard. The app is ‘four-part multi-timbral’ which means that you can actually load four different sounds at any one time and trigger each of these independently via a different MIDI channel number or, if you wished, layer multiple sounds.

In terms of the sounds themselves, these are split into 16 categories; Drums,
 Guitar, Piano, Electric Piano, Organ, Chromatic, Strings, Brass, Woodwinds, Lead Synth, Synth Pad, Voices, Ethnic, Percussion, and Sound FX. The free version of the app is supplied with a single sound in each category purely for demonstration purposes but the paid version, at UK£13.99, comes with around 140 instruments. If you happen to own an iRig MIDI device, you can add a further 48 instruments when you register it.

SampleTank; a broad palette of sounds and MIDI performances in the paid version with more available via IAPs.

SampleTank; a broad palette of sounds and MIDI performances in the paid version with more available via IAPs.

However, there are also a large number of in-app-purchases that allow you to add even more instruments. These include an ‘All Sounds Pack’ option (UK£27.99) plus two premium packs – the Miroslav Philharmonik Mobile Edition and the Sample Moog Mobile Edition (both UK£13.99) – that obviously expand the sonic possibilities. The Miroslav option is one that may well interest quite a lot of potential users as one of the consequences of it being more difficult to construct detailed sample-based instruments given the iPad’s more restricted storage capacity is that realistic sampled-based orchestral instruments are a bit thin on the ground.

In addition, for each instrument category, SampleTank is supplied with a collection of what are essentially MIDI loops. Once you load an instrument you can, therefore, trigger the playback of one of these ‘grooves’ from the set associated with that instrument category. And as the app includes the ability to create presets based upon a set of up to four instrument/groove combinations, and as you can then trigger these presets in real-time, you could easily imagine building a song idea or performance from them. Equally, you can trigger grooves on the fly via the touchscreen and the app also includes a four-track MIDI recording function.

In terms of sheer power or features or even sample depth, SampleTank for iOS is not going to challenge the leading desktop sample-playback engines anytime soon. However, as a source of sample-based sounds for composers or performers or songwriters, personally I think it is the best ‘all-in-one’ solution iOS currently has to offer. It is well-featured, generally easy to use and, providing you are willing to invest in some of the additional content (which does, of course, raise the overall price), stuffed full of very useable sounds. It is also a universal app so works with both iPad and iPhone.


soundfont pro logoSoundFont Pro

In essence, SoundFont Pro (UK£6.99) is a four-part multi-timbral sample-based virtual instrument for iPad. As we will see in a minute, there is actual more to it than that but what this means is that the app can respond to as many as four different MIDI channels at once, meaning that you could easily build a four-part (sound) musical arrangement with a single instance of the app (providing, of course, you had a suitable MIDI sequencer running alongside SoundFont Pro).

SoundFont Pro is so named because it makes use of a sample format know as the soundfont. This was created back in the day when even desktop computers couldn’t cope with large sample sets and it is generally a compact sample format. However, it got quite a cult following and, as a result, lots of user-created soundfont sample sets can be found scattered around the internet. This is a great way of expanding your sound sources for little or no additional cost and such soundfonts can be loaded into SoundFont Pro for use in your own music projects.

One nice extra twist in SoundFont Pro is that within collection of sounds you have loaded into it at any one time (the app refers to this as an ‘arrangement’) you can specify four ‘zones’. Each zone can be thought of as a keyboard split – a range of notes across the full span of an 88 note piano keyboard – within which the zone is active.

SoundFont Pro - a multi-timbral sample-based instrument for iOS.

SoundFont Pro – a multi-timbral sample-based instrument for iOS.

Within each zone you can either load a single soundfont instrument or, if you want, layer two different ones. This is great for creating more complex sounds from even quite basic soundfont sample sets. If you do have two layers loaded within a zone, both layers respond to the same range of keys. Obviously, with four zones fully occupied, that’s a maximum of eight soundfonts loaded at any one time.

This combination of zones and layers provides a lot of flexibility. You can specify the MIDI channel that each zone responds to. So, for example, you could have all the zones operating on different MIDI channels and this would be how you would create a four-part multi-timbral configuration. In this case, it wouldn’t matter if the note ranges of the four zones overlap as each will only respond to MIDI note input on the specified MIDI channel.

The interface is well-designed although it does take a little time to get your head around the various elements of the arrangements and zones. SoundFont Pro may not be the most spectacular iOS music app you might choose to ever use, but it is a solid, cost-effective (for those on a tight budget), sample-based sound source that would do a good job in either a live or recording context.

SoundFont Pro

bs-16i logobs-16i

Bismark bs-16i (UK£5.49) provides another soundfont-based virtual instrument collection. It only takes up about 50MB of space but provides a very respectable SoundFont-based sample library covering a wide range of GM-style instruments. The quality of the sounds is actually pretty good and, as it supports both Audiobus and IAA and the size of the keys can be adjusted to suit even the stubbiest of fingers on the relatively modest iPhone screen, it does the business with a minimum of fuss.

Bismark's bs-16i provides a good palette of basic sounds to work with on both iPhone and iPad.

Bismark’s bs-16i provides a good palette of basic sounds to work with on both iPhone and iPad.

The other advantage of bs-16i is that it is 16-part multitimbral. With a suitable MIDI sequencer 9such as Cubasis) you could, therefore, play 16 different sounds via bs-16i at the same time, all playing back MIDI parts from different MIDI tracks. The interface is very straightforward and, while it doesn’t offer you masses of options in terms of tweaking the basic sounds, it is very easy to find your way around and provides excellent value for money.


thumbjam logoThumbJam

ThumbJam by Sonosaurus is a very different type of app to the previous three mentioned. While it provides a good range of sample-based sounds for you to play with and can also be used in a multi-timbral mode playing back multiple different instruments at the same time, perhaps its real strength and selling point is the performance interface. This makes tremendous use of both the touchscreen and the motion sensors in your iDevice. The result is that, even with a fairly modest sample base for the sounds, you can coax some really expressive performances from the sounds.

ThumbJam's interface might look a little plain but it is very playable.

ThumbJam’s interface might look a little plain but it is very playable.

The app is universal (iPad and iPhone) and includes Audiobus and IAA support. The playing interface can be used to send MIDI data to other apps (so it also doubles as a MIDI performance app) and, if you want to sing or play a single-note melody line into the app via an instrument, it will make a pretty good stab at audio-to-MIDI conversion. At UK£5.99 this is a bit of an iOS music classic. If money wasn’t such an issue, I might choose it alongside one of the three mentioned above rather than as a direct replacement. Either way, ThumbJam is certainly worth owning.

Download from iTunes App Store

Guitar apps

Of course, sample-based virtual instruments don’t have to cover all the instrument classes; you also get those that specialise on a single instrument type. For guitar and bass guitar there are actually quite a few options on the App Store but I’ll highlight three of my particular favourites here.

guitarism logo 2Guitarism

The iTunes App Store is full of lots of ‘playable’ virtual instruments but, as a guitar player, if I had to pick just one, it would be Guitarism. The basic app is currently free but is offers a number of in-app- purchases that expand on the features and the range of available sounds (including some electric guitars). These are well worth exploring so budget for some of these from the start; it is still excellent value for money.

The attractiveness of this app is not that it is stuffed full of features or that it is based upon the most sophisticated of multi-layered samples (although the sound itself is actually very good). What makes the app useful is that, with a modicum of practice, it is actually quite playable. Sure, if you try to play high-tempo strumming, that can take a lot of work to get right and any mistakes you make can easily reveal the ‘not a real guitar’ nature of what Guitarism generates. But, for medium and low tempo strumming, you can create some remarkably convincing performances. And, in the rather neat additional tilt and mute features, you have plenty of performance options, all of which are relatively easy to learn.

Guitarism now has electric options via the Rockstar Collection IAP - and still works great with Audiobus.

Guitarism now has electric options via the Rockstar Collection IAP – and still works great with Audiobus.

Nope, I’m not going to sell my Taylor acoustic and replace it with Guitarism but, when I’m out and about without my guitar and need something to knock a few chords out on, Guitarism is well worth pulling my iPhone (or iPad as it is a universal app) out of my pocket for.


ifretless new logoiFretless Bass

For bass players, iFretless Bass is not quite the same sort of beast as Guitarism. The latter is great for some very wholesome strumming but iFretless Bass is a more heavyweight app altogether. Indeed, when it comes to bass guitar sounds, the detailing in the sampling used in iFretless Bass means it is probably the most sophisticated virtual bass instrument currently available for iOS. The sounds cover fretless and fretted bass styles as well as an acoustic bass and a few synth sounds. Make sure to listen on decent headphones or speakers though just to get the full benefit of the rather wonderful bottom end; the sound is very solid.

iFretless Bass now includes support for IAA.

iFretless Bass now includes support for IAA.

At UK£6.99, iFretless bass is a good deal just on the basis of the quality of the samples. However, you also get the rather brilliant user interface. With virtual strings and frets that will make bass and guitar players feel quickly at home, the app includes some fabulous performance options such as velocity sensitivity, hammer-ons, slides and vibrato. And as the app also supports MIDI in and out, you can use the interface to control other iOS music apps if you wish. For guitar shaped fingers, this is much better than using a virtual piano keyboard. iFretless Bass also includes Audiobus support (see below) and inter-app audio (IAA) so it is also great as a source of bass sounds in a recording context.

iFretless Bass

iFretless guitar logo 2iFretless Guitar

For iFretless Guitar, you can pretty much take as read the entry above. This uses a very similar sound engine to iFretless Bass but it is populated with guitar samples rather than bass guitar samples. It is equally good. iFretless Guitar is perhaps better at melody/solo performances that pure strumming when compared to Guitarism but the sound is great and the performance interface very clever.

iFretless Guitar - the main interface will be familiar to users of iFretless Bass.

iFretless Guitar – the main interface will be familiar to users of iFretless Bass.

There is a nice selection of basic guitar tones spanning nylon acoustic through to crunchy ‘rawk’ electric. You also get some basic effects although you could, of course, feed the output of iFreless Guitar through a suitable guitar amp sim app if you wanted more detailed control on the amp/effects end of the sound.

iFretless Guitar

Piano apps

Virtual keyboard instruments are not, of course, all about synths; pianos are required also. There are lots of virtual acoustic pianos apps on the iTunes App Store and, while some such apps used synthesized piano sounds, more commonly these are sample based. The problem with the majority of these, however, is that sound quality and playing detail are often sacrificed for keeping the size of the samples in check.


This is not the case with IK Multimedia’s iGrand sample-based acoustic piano app and the key sale’s pitch is that the sampling is more detailed than any other piano app currently available. Personally, I think this is a pretty fair claim and, while the app takes up a fairly substantial 256MB, in use I actually think it packs a punch well above its sample weight.

There is a basic free app with a single piano but the paid version (currently UK£13.99) provides some 8 different pianos, while a further IAP expansion pack (at UK£6.99) adds nearly 9 further pianos suitable for jazz, rock, pop and other musical styles. While you can undoubtedly buy more detailed sample-based piano instruments for the desktop (where sample storage is less of an issue), you will also pay considerably more and iGrand manages to strike an excellent balance between sound, a compact footprint suited to the iPad, and price.

iGrand probably offers the best sample-based acoustic piano sounds currently available under iOS

iGrand probably offers the best sample-based acoustic piano sounds currently available under iOS

There are enough sample layers used to give your performance some genuine character and if you do use your iPad for live performance (hooked up to a suitable hardware MIDI keyboard), iGrand would make a perfectly respectable sound source for all but the most demanding of contexts. And with Audiobus support included, it is also the best source of acoustic piano sounds available for an iOS recording system.


ilectric logoiLectric

Pretty much everything I’ve just said about iGrand also applies to IK Multimedia’s iLectric and, as the name suggests, this provides a suite of classic electric piano instrument, all with very detailed sampling to give a rich – and very playable –sound. The basic app is priced at UK£13.99 and includes 20 electric piano and clavinet sounds, with a further 20 available via an IAP (UK£6.99). The sounds are universally good with patch names such as ‘Suitcase EP 1’ or Wurly Stage’ giving a clear idea of what the sound is based upon.

For electric piano sounds, iLectric is pretty hard to beat at present.

For electric piano sounds, iLectric is pretty hard to beat at present.

As with iGrand, the interface is stylish and very easy to use. The app also includes a very nice control strip providing access to effects such as EQ, reverb, overdrive and modulation effects (chorus, phaser, tremolo, autopan and flanger). Like iGrand, Audiobus support is included and, hooked up to an external MIDI keyboard, this would make a very nice electric piano sound source for a performance context.


neo-soul keysNeo-Soul Keys

The other top-notch options for electric piano sounds is Neo-Soul Keys. The basic app is universal (it supports both iPad and iPhone) and is actually free. However, the free version is ‘ad supported’ and, to remove the ads and to access the full range of electric pianos available, you can choose from a number of IAPs.

With MIDI and Audiobus support, the app is easy to use in either a recording or a live performance context and, like iLectric, it is quite a sizeable app (681MB). However, the sounds themselves are very good.

NeoSoul Keys provides some great electric piano sounds. The app is really designed to be played with an external keyboard but there is a virtual keyboard that can be opened if you need it.

Neo-Soul Keys provides some great electric piano sounds. The app is really designed to be played with an external keyboard but there is a virtual keyboard that can be opened if you need it.

You probably don’t need both iLectric and Neo-Soul Keys (unless you are a real electric piano die-hard) so the option to try the sounds before you buy is a very useful one.

NeoSoul Keys

Best of the rest apps

There are lots of other virtual instrument apps available on the App Store – some good, some bad and some downright ugly – but a couple are worth adding as an ad hoc ‘best of the rest’ just to finish off here.

ifretless sax logo 2iFretless Sax

At the time of writing, the most recent addition to the iFretless series is priced at UK£6.99, and as you might expect given the title, takes the general iFretless concept and applies it to that most expressive of instruments; the saxophone. The same detail and depth exists within the underlying sampling as in the other iFretless apps and, as a consequence, once you get your head (or fingers) around the subtleties of the performance interface, it is possible to coax some remarkably realistic performances from the app.

There are several sax instruments and also a clarinet and bass clarinet and each of the instruments has a distinctive character. For example, the bass sax is suitable deep, the tenor can go from soft and sleazy to punchy and the alto has a slightly lighter tone. As anyone who has tried to muster a realistic ‘sax’ performance out of a sampled instrument will tell you, it is actually a very difficult thing to pull off. In the main, this is because the instrument itself is so fluid and expressive; trying to recreate that with samples is quite a challenge and attempting to do it via a traditional piano-style MIDI keyboard – without some considerable practice and expert pitch wheel work – just adds a further obstacle. In that regard, the string-based interface of iFretless Sax with its ability to add slides and finger vibrato is a big plus. Again, master the playing interface and you can get some impressive sounds from the app.

iFreless Sax uses the same performance interface as iFretless Bass but, this time, with a suitably brass-like colour scheme.

iFreless Sax uses the same performance interface as iFretless Bass but, this time, with a suitably brass-like colour scheme.

A virtual sax is perhaps a bit of a niche product in the world of music technology (mobile or desktop) but, if you do like your iOS music productions to contain a bit of sax, iFretless Sax is currently the best way to add it. Rumour has it that ‘iFretless Strings’ (or something similar) is on its way; that would be great to see (and hear).

iFretless Sax

futulele logoFutulele

If you have given Guitarism the once over then the basic concept behind Futulele will seem familiar but applied, of course, to the Ukulele. The main playing interface for Futulele is a doddle to use; you strum the strings and use the green and blue arrows to step forwards (or backwards) through the currently selected chord sequence. The hand icon button produces a staccato-style chord while the small ‘six box’ icon opens up the chord sequence programming page. This is also very easy to navigate and you can program sequences long enough for almost any song format. Chords themselves are simply dragged and dropped into the sequence slots and there are plenty of chord types available to keep all but the jazz ukulele players (are there any of those?) happy.

Futulele's main playing interface is easy to learn. Even if you have never played a ukulele before, you ought to be able to get something musical out of the app in just a few minutes.

Futulele’s main playing interface is easy to learn. Even if you have never played a ukulele before, you ought to be able to get something musical out of the app in just a few minutes.

Futulele is a lot of fun to use and very easy to get to grips with but don’t be fooled by the rather cheesy Hawaiian graphics; it also sounds pretty good. On the iPad you get slightly more control over chord switching (it’s more like Guitarism) but Futulele is another example of an iOS music app that does one thing but does it rather well. At £1.99 (or the equivalent $/€ price) it is a lot of fun for not a lot of money. If you fancy a little bit of virtual ukulele, Futulele is well worth adding to your app collection.


In summary

I think it’s fair to say that, for sample-based virtual instruments, iOS doesn’t fair anywhere near as well as the desktop. This shouldn’t perhaps be such a surprise; the hardware – while brilliant – still operates within some constraints that (RAM and storage space) that particularly influence just what can be done in building detailed sample-based playback engines. We are some distance yet from seeing the equivalent of Native Instrument’s Konkakt running on an iPad.

However, that’s not to say what is available isn’t very useable; it is. Equally, while it is all too easy to see a UK£13.99 app as ‘expensive’, compare that to the prices paid for desktop virtual instruments and it is difficult to argue that any of the apps listed above don’t punch above their price.

Hopefully, if you need either an all-in-one virtual instrument app to cover a range of musical bases, or whether you just need something targeted at a specific instrument, there are some possibilities here for you to explore. Happy music making….  and don’t forget to check out the other ‘roundup’ articles looking at different categories of iOS music apps.

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