As someone with what might best be described as an ‘untrained’ singing voice, I’ve always been a sucker for software that can give the less than confident singer in me a helping hand. On my desktop system, I have therefore used all the mainstream vocal processing products. Aside from those that provide a distinctive sound (effect chains of compression, EQ, delay and reverb, etc.), two sorts of tools stand out here; pitch correction and harmony generation.
Both of these sorts of tools have been around in desktop format for a number of years and both have corrective and creative uses (yep, even that Cher-inspired ‘Believe’ vocal tuning effect which has now been done to death) but it’s now great that similar tools are finding their way into the world of music apps for mobile music making. So, for example, Auria has Mu Technologies ReTune plug-in for pitch correction and this is capable of some excellent results providing – like most pitch correction tools – you don’t expect it to perform miracles. It’s perhaps not quite in the same class as an Autotune or Melodyne but it is not very far off.
Companies like Antares and TC Electronic (including the TC Helicon brand) have included vocal harmony products – both software and hardware – in their catalogue for many years and are probably the market leaders in this technology. However, other companies also operate in this arena and, while VirSyn are probably best known for their synth-based products (including the excellent iOS Addictive Synth and iSyn Poly) and effects processing, they also have the Windows/Mac Klon plug-in for pitch correction and harmony generation and the iOS vocoder app iVoxel. The latest release is Harmony Voice, an iPhone/iPod, iPad app that brings some of Klon’s harmonisation functionality to the iOS platform.
As its name suggests, Harmony Voice’s primary purpose is the generation of harmony parts and it can generate up to a four-part harmony in realtime from the audio input signal – most obviously a vocal but it could equally be a monophonic instrument line – while also adding some pitch correction, although the app is not really intended as a full-on pitch correction utility and so shouldn’t be considered as an alternative to something like ReTune.
The app features a number of different harmonisation modes. For instant gratification, there is a fully automatic mode. However, if you want more control, there are other modes available. For example, you can use the onscreen keyboard to add up to four harmony notes where the keys you play define the intervals between the harmony notes rather than the absolute pitches of those notes. Alternatively, a further mode lets the notes you play on the onscreen keyboard define the absolute pitches of the harmony parts. Finally, a further auto harmony mode generates the harmony parts automatically but the input pitch is determined not by what you sing but by the melody to play on the keyboard. Providing you have a suitable MIDI interface, Harmony Voice can also take its note input from an external MIDI keyboard rather than the virtual onscreen version.
In all cases, there is intelligence used in the harmony generation as you can specify the key and scale settings. A very good selection of preset scales are available including variants of chromatic, major, minor, pentatonic and some more esoteric offerings such as Egyptian or Hawaiian.
Other key features include a selection of effects that can be applied to the audio. These include chorus, delay and reverb. There is plenty of control offered here and, while I perhaps would not choose the reverb as my main weapon of choice for a really exposed lead vocal, on backing vocal parts or on a lead vocal in a busy mix, the results are actually pretty good. Other processing options include the ability to vary the degree of pitch correction applied to the harmony parts and the option to adjust their gender, presumably achieved by manipulating the formants within the signal. There is also a metronome feature and the ability to playback a backing track while you sing live into the app and experiment with the different harmony options. If you have recorded your song in a multitrack app such as Garageband or Auria and want to generate some harmony backing vocal parts, this would be very useful.
Finally, there is a record function that allows you to capture the output of your harmony generation as a WAV file. From here, it can then be exported via iTunes or through the support for Audiocopy and SoundCloud.
As shown by the various screen shots, access to this feature set is spread out over a number of different screens within the app. In use, navigation through these various functions has been well laid out and the app is pretty intuitive in use. While a little music theory is always a help when constructing harmonies (vocal or otherwise), Harmony Voice generally makes it fairly easy to experiment with the different options – although don’t expect instant results – you need to spend some time getting your head around the different harmony modes before you can really start to get the best out of the app and be genuinely productive. Each of the harmony modes has its own use and it can take a little while to appreciate exactly how each operates and what situations it is best suited to.
Of course, all this functionality doesn’t matter too much if the multiple versions of your voice (or instrument) that the app creates sound like some kind of robot cartoon character (unless, of course, robot cartoon voices are exactly what you are looking for!). Fortunately, that’s not the case and, given a suitably respectable input signal – both in terms of audio quality and, to an extent, singing performance – the audio quality of the harmony voices is actually pretty good. Indeed, while the world doesn’t really need more of my own singing voice than I can produce in isolation (!), me plus a few harmony parts even allowed me to surprise myself. But it is worth saying again for emphasis – the better the quality of the audio input, the better the quality of the harmony output – so if you have access to a good add-on audio I/O device to use with your iOS device, you are much more likely to get useable results than if you are using a combination of the built-in mic and headphones, although these do obviously work.
Tapping the Song tab opens up a rather nifty looking turntable graphic that allows you to load a backing tracking from within your iTunes library. This worked well enough and means that you can actually experiment with generating harmonies in the context of your own song projects.
Bringing harmony to the world
So, the basic harmony engine does decent job; perhaps not up to the standard of some of the very best offerings available in desktop software or an external hardware device (all of which come with a price tag considerably higher than the £2.99 VirSyn are currently asking for Harmony Voice) but still useable provided you (a) put in the effort to grasp that creating harmony parts requires some understanding of harmonisation and (b) you get the quality of the audio input right.
However, if you want to take your harmonised vocals out into the wider world – for example, to use Harmony Voice as a tool in your overall iOS based audio recording workflow – in the current version of the app at least, there are a couple of catches. First, the record option, which allows you to engage the record mode and then, while audio recording goes on in the background, records your harmony parts, if you have a backing track playing, also records that. What you end up with, therefore, is a mix – and perhaps not the exact mix that you might always like – of your backing track and the harmonies. This means you can not, at present, monitor the backing track, record just your harmonies and then export just your harmony parts back to your iOS DAW app (for example, Auria), to mix balance or process them in other ways.
Second, and this is perhaps more of an issue when you have your ‘producer’ hat on rather than your ‘singer’ hat on, is that Harmony Voice currently only works with a live vocal input; you actually have to sing into it to get the harmony engine to do its stuff. What you can not do – again in the present version at least – is take a vocal recording you have made elsewhere, load this into Harmony Voice to use as your voice ‘input’ and then loop the playback of this vocal track while you experiment with different harmony options before recording the final harmony voice output and porting it back to your DAW. I think lots of iOS musicians, who are building pretty sophisticated and feature-rich recording workflows around multiple apps, would see this as an optimal way of working with Harmony Voice as part of such a workflow.
Despite my two item ‘I wish it did this’ feature list above, I think it is worth emphasising that Harmony Voice is more than just a gimmicky generator of backing vocal parts to keep your mates entertained once you have all completed Angry Birds. Underneath what is a well-designed user interface is a very respectable audio harmony engine. The combination of the various harmony modes provide a good deal of musical intelligence and, in turn, require some equally intelligent input on behalf of the user to get the best from what the app can offer. But that best is actually pretty good.
Qualifiers about the requirement for decent quality audio input taken as a given, the quality of the audio output, when the app is used with some common sense, is good. So, Harmony Voice is certainly not a toy or a vocal gimmick; it has the potential to be a genuinely useful app for the serious iOS recording musician.
I really hope VirSyn can continue to develop the app – particularly in making it easier to fully integrate into a wider iOS-based recording/demo production process – and develop on that potential. While I’m no programmer (that was in a former life, many years ago), I think the genuinely difficult stuff – creating the harmony engine for example – has been done. Fingers genuinely crossed that VirSyn can keep at it as I think this would widen the appeal of the app considerably amongst the rapidly growing, iOS music making, user base. All that said, even as it stands, at £2.99 (or the equivalent $/€ price), Harmony Voice is a steal and well worth experimenting with.
Update: VirSyn have updated Harmony Voice to v.2. This addresses the key limitations I identified above in my original review. Full details of the update can be found here.