Teaching audio and MIDI editing in the MOOC

This is the fifth in a series of posts documenting the development of Play With Your Music, a music production MOOC jointly presented by P2PU, NYU and MIT. See also the first, second, third and fourth posts.

Soundation uses the same basic interface paradigm as other audio recording and editing programs like Pro Tools and Logic. Your song consists of a list of tracks, each of which can contain a particular sound. The tracks all play back at the same time, so you can use them to blend together sounds as you see fit. You can either record your own sounds, or use the loops included in Soundation, or both. The image below shows six tracks. The first two contain loops of audio; the other four contain MIDI, which I’ll explain later in the post.

Recording audio is a vast topic unto itself. If you’re just getting started, there are two approaches:

1. You can use the mic built into your laptop, which is expedient, but sounds terrible.
2. You can get a decent microphone and a specialized audio interface, which is more complicated and costs money, but sounds way better.

Make sure you’re somewhere quiet while you record. You’ll probably notice that it’s difficult to find a balance between your recording being too quiet and too loud. You’re not the only one who finds this to be tricky. The easiest solution is just to experiment with the placement of the microphone and sound source(s) until you get a reasonable level.

The spiky waveforms in the audio track represent the amplitude (loudness) of the sound. The top track contains drums, which have a characteristic look: big sudden spikes that taper quickly to silence. The other audio track looks like it contains drums too, but it’s actually piano played in a percussive style. Both are loops that came with Soundation. They’re conveniently tempo-synced, meaning that they line up neatly with each other, and with any other loops I might add. Audio that I record myself won’t be so neatly lined up, unless I put in a lot of effort to make it so.

And so what about the MIDI tracks? MIDI stands for Musical Instrument Digital Interface. It was designed in the 1980s as a way for computers to talk to synthesizers, and for synthesizers to talk to each other. The MIDI tracks above do not contain any sound. Instead, each track is a list of notes that are to be played by the software instruments (SPC, drum machine, etc.) MIDI is like sheet music —  it doesn’t make sound by itself. Instead, it’s a set of instructions for a thing that makes sound. Just like a piece of sheet music can be played on piano or violin or oboe or whatever, a MIDI file can be played back on synthesized piano or violin or oboe or whatever.

It’s easy to get confused between audio and MIDI. Computers have synths built in, so if you have a MIDI file, you’ll be able to listen to it played back on a dinky piano sound. But it’s your computer providing the dinky piano, not the MIDI file. Soundation adds to the confusion by listing its assortment of prefab MIDI loops under “audio.”

MIDI is way easier to deal with than audio in a lot of ways. Audio files are enormous — CD-quality stereo sound is ten megabytes a minute. MIDI files are trivially small, a few kilobytes at most. MIDI is also easier to create and edit than audio. You can enter MIDI notes with a keyboard, or just draw them onto the screen with the mouse. (I’m a lousy keyboard player, so for me the mouse method is a lot faster.) Once the notes are in the editor, they’re like text in a word processor. You can delete, cut, copy and paste. You can select a bunch of notes and change their length, or loudness, or transpose them. And you can play them back using any synth sound available on your computer.

Soundation includes a diverse set of MIDI-controllable software synths, some of which are quite nice:

• Simple — a very basic and not very exciting synth.
• Mono — a somewhat more versatile groovy retro synth.
• Supersaw — a contemporary-sounding synth.
• DrumMachine — a drum machine, surprise! Defaults to 808-like sounds.
• Noiser — makes white noise. The musical application is not totally obvious, but I guess if you put the right effects on it you could make cool textures or percussion.
• SAM-1 — a sampler that gives you some “acoustic” sounds, like piano, organ, guitar and strings. The sampler works by playing back recordings of single notes played on each instrument. Sampled piano and organ tend to sound quite convincing; sampled guitar and strings tend to sound totally fake. Though fake can be its own aesthetic virtue in the right context.
• GM-2 — another sampler with more keyboard sounds.
• The Wub Machine — a dubstep bass, which goes literally goes “wub wub wub,” and also makes many other cool synth sounds.
• SPC — Soundation’s version of the classic MPC sampler, with some pretty sweet drum sounds.

Both audio and MIDI can both be edited by manipulating the rectangular blocks, known in most audio software as clips. You can resize the claps, drag them earlier or later, copy and paste, and so on. Soundation has an additional nifty feature: if you drag a clip by its upper right corner, you automatically loop it, which is handy. However, Soundation is not a wonderful audio editor in other respects. The cursor doesn’t snap to the closest barline when you’re zoomed out. In other words, there’s no way to make exact edits at the macro level. If you want to split your loops up into verses, choruses and so on, you have to do a lot of tedious zooming in and out.

It feels petty to complain about the limitations of a free in-browser tool, but if you want to get serious about audio and MIDI editing, you’ll eventually need something more sophisticated. That’ll be the topic of another post.