Here’s another Disquiet Junto piece, title Risset’s Walk

I use Renoise for pretty much all my music making.

A little while ago I learned of the “FX” commands that can be added to any line of any track, commands that can alter either a particular note or some global behavior. I started looking at these and one of them allows you to change the current BPM. Sweet.

Another commands allows you to shift the pitch of the currently plating note, to get a sort of glissando or “bent” quality.

While dozing off the other night I was thinking of these two effects, pitch shifting and tempo changing, and how I might use them as the underpinning of a Junto piece.

Some years ago I learned of Shepard Tones; it’s an audio illusion where a sequence of notes seems to get endlessly higher (or lower) in pitch. Of course that’s not what really happens. It’s a neat trick of volume and timbre fading. I wondered if the same could be done with tempo. If you gradually slowed down a beat of whole notes while also gradually adding in corresponding half notes, by the time you got to half tempo it should sound the same. I thought of it as “Shepard beats”, decided this was a brilliant insight, and fell asleep.

The next day I was all excited by my amazing musical discovery. By evening, though, Google informed me that a gentleman named Jean-Claude Risset thought of this back in the ’60s.

In fact, Risset also came up with a variation on Shepard tones using a continuous glissando.

Still, while my idea was not novel I was unaware of any actual composition that made explicit use of this approach to tempo adjustment (or Shepard tones, for that matter). There are all sorts of “gee whiz” demos but no actual music.

So this Junto piece, “Risset’s Walk”, tries to take the Risset tempo change idea and apply it to a coherent piece of music.

The piece is in three parts. Each starts at 190 BPM (more or less; the values are specified in hex) and shifts down to 95 BPM. During this transition there are percussion elements that fade in, as well as some additional rhythmic elements that attempt to keep the ear from noticing (too much) this change in tempo.

Over this is a combination of piano and synths. The trick was to alter the melody such that as the tempo was slowing the music was still filling a somewhat constant rhythmic space.

By no means is the tempo change hidden but the looping from full to half speed and then right back to full works pretty well.

It was done fairly quickly, and repeated listening point up sections of sloppiness. Some of the piece was hand-edited (the underlying percussion, for example, was keyed in and volume automation was hand-drawn). The melody parts were recorded live, then edited to fix assorted flubs. The sloppiness aspect is interesting; it seems that to mask the tempo change you can add filler notes and adjust phrasing. Because the tempo is not fixed this is a little tricky to get right. But the feeling of sloppiness might come from trying to have live playing partially adjusted for some after-the-fact quantization. In other words, hearing the sloppiness provided some insight on how one might approach this sort of temp change.