How to create a virtual instrument

You don’t need to know anything about making music software to make virtual instruments.

You can map samples in soft samplers. A sample is a recording. Mapping means assigning them to keys and/or velocity ranges. A soft sampler is a computer program that plays back specific samples at the moment they’re triggered.

Sampled instruments are fun. You can use instruments that don’t exist, use existing instruments in ways that are not possible, get music out of instruments you can’t play and build an instrument collection you can’t have in the physical world.

You could start making instruments today, without spending money, for example by downloading the Sfz player Sforzando, audio editor Audacity and the Digital Audio Workstation Tracktion 5. For Windows there are Sfz creator tools like sfZed. If the instrument you want to make already exists virtually, it’s usually better to buy them though. If you charge yourself for the time you spend on making an instrument you’ll find out it’s cheaper to buy.

I never made an instrument with Sforzando – paid software like Logic and Kontakt is so much easier – but it’ll be easy to find out by reading some pages on the internet, I’m just covering the basics here!

Samples need to be tuned, leveled and aligned. An untuned instrument simply won’t play well with others. Hopefully, Sforzando can tune samples individually, that’s the easiest way. Just play the sample, run it through a tuning plugin like Tune it! and tweak the tuning in the soft sampler until it’s in tune. Samples can also be tuned in Tracktion, using a tuning plugin and rendered after they’re good. At the moment I tune samples in Kontakt 5 and then pitch shift them in the same amount of cents in Sound Forge. It’s usually an unnecessary step, the soft sampler will remember the tuning. You can pitch shift in Audacity too. Samples need to be loud enough compared to each other. How loudness differs over the keyboard is a matter of taste. I change the loudness the same way I change the pitch, I play with a fixed velocity though.

Alignment can be done in Tracktion, it means that all notes need to start at the same time. Place the first two samples above each other, move them until the sound starts at the same time, keep adding new samples while repeating the process. Keep the first one as a reference, mute the rest. When all samples are aligned, cut off all starts at the same point and render the files. It can look like this, but more space before the sound starts is also possible ->

Myriad – OSX only – is capable of cutting off the start of samples at a fixed amound of samples before the peak. I’m going to try that for one of my next products. It’s also a crazy good batch processor for all sorts of things you want to do with every sample of an instrument and has more useful tricks and tools.

This is what a simple map can look like:

One sample for each key. It’s also possible to stretch samples over multiple keys, the soft sampler will change the tuning during playback! It was common practise in the first years of this century because computers were less powerful. Since 2014 instruments are being made with hundreds of samples mapped to a single key in one instrument.

Sample Alignment:

Velocity layers add to realism. Velocity is the translation of the speed a key is struck with, midi divides it into 127 steps. Samples for each of the 88 keys may sound great, but a virtual acoustic piano is better off with 3 velocity layers and 30 keys because a piano sounds very different if you play it soft – it’s not just softer. Compare sampling an instrument to making a picture though: more pixels will make the result less digital. 30×3 is not as good as 88×4. Wait, 88×10. Now we’re talking! Michiel Post, Sampletekk and Native Instruments started doing that in 2004. Midi is capable of 127 layers though, why not 88×127? And why not trigger alternative sample groups every time a key is struck. We call those Round Robins. That’s how you end up with hundreds of samples per key and virtual pianos that use over 60GB of samples. The auto-sampling technique of companies that make instruments like these is such that aligning and leveling of over 100,000 samples is not needed.

Velocity layers:

Autosamplers are programs that trigger a note via midi, record their input and map everything for you, they save tremendous amounts of time (and all cost money). Samplit adds a nice function to that: it tells you what note to play and records you when you play it. You don’t need to name or cut when you’re done sampling. Other Autosamplers are Chickensys Translator, a true veteran in computer- and sample technology, Samplerobot – a windows program that uses Wine if you want it to run on OSX – Apple’s Mainstage and Extreme Sample Converter, an abandoned Windows only program that’s still for sale and has the best loop finder algorithm I’ve tried.

Sampled instrument developers brag about “unlooped samples” and they should. To save space, samples used to be shortened to a point where a part at the end could be repeated – looped – while maintaining the character of the instrument. So you have the “attack”, the start of a note, and then the same part over and over again while fading out, or sustained until released. The instrument freezes in time, the last part of a note is just like the middle part. Maybe softer.

On modern computers these short samples are no longer necessary, long sustained notes and natural decays can be used without freezing. Loops can be fun though to make long, sustained samples infinite. There’s often a point at the start of a 30 second file that can be combined with a point at the end of the file. For my upcoming product I used Extreme Sample Converter to find good loop points. EXSC even creates crossfades inside the files if you want to.

Finding loop points:

(edit: contest over! it seemed really hard, only one person guessed right)

Last thing: I want to have a little contest here. I’m almost done with my next product. It’s a collection of instruments turned into one, like a drumkit or a church organ, except there’s only one of these ever built – a hybrid, custom instrument. Even the individual instruments have never been sampled like this before. I’m dying to know how long it takes before the first person knows what I sampled!

So listen carefully and post your guesses here – the first one who guesses right will get it for free! (People who already know what it is are ruled out from this contest, you’ll get another shot.)
Make sure I can contact you in case you win, use a name I know or enter your info on the “stay informed” page.

I will make versions of this instrument for Kontakt, GarageBand/Logic, Halion and in SFZ format that will work in free software like Sforzando.