Vocal Synthesis Using Percussion
Preface
Using the same concept as frequency chaining, one can generate vocals on OS. However, they are difficult to recreate by hand and require an external tool to easily automate frequencies for sequencer use.
Vocals are made up of a range of frequencies (as opposed to being isolated to one tone)—on top of constantly shifting pitch to ever pinpoint accurately. If you’re interested in this jargon, I suggest reading up about it here.
Chances are, you have seen an MP3 to MIDI conversion sequence on the site. This kind of conversion analysis is known as FFT—in which notes are assigned across the piano roll in order to best represent the audio sample. Audio clips generated this way tend to be very messy and rather impractical to use in a legitimate song.
Instead, we will use a PCM converter to generate audio samples on OS. I asked the user Frank how he was able to automate the drum frequencies for this sequence. In response, he released a user-friendly version of the PCM converter he programmed for it, which I’ll explain how to apply in this article.
Through PCM, audio is also generated physically from grouping tiny notes at a specific rate. It is more accurate than FFT conversion as it is able to represent all frequencies outside the 12-tone equal temperament system.
The other benefits to PCM is that the clarity is great and doesn't require cleanup unlike FFT converted samples. PCM samples are also flexible across multiple drum kits allowing for various sound textures—whereas FFT isn't, being limited to 8-bit Sine.
The downside to using PCM is that it outputs a mass number of notes in order to replicate note frequencies. OS has a tendency to lag and break audio under high-density situations, therefore making this one of the more difficult techniques to control. After conversion, this technique requires a lot of post-maintenance in order for your sequence to play properly.
This article will guide you on how to obtain PCM samples, as well as handing out some general tips and discussing other miscellaneous items that are related. This technique requires a strong computer to run—if you have difficulty loading some sequences, it is recommended you do not use it.
For reference, here is a song that I've made using percussion-chained vocals. It showcases how to effectively use these vocals on OS, as well as gauging how intensively it will run on your computer.