Set tempos and global time signatures

Set tempos with setcps

Tempos are specified using the setcps function, e.g., setcps 0.5625 (this is the default value, which corresponds to a bar at 130 BPM in 4/4 time).

To convert from BPM to CPS, you can do the maths right in the function. For example, to set the tempo at 130 BPM, use setcps 130/60/4. We divide by 60 because we are converting from beats per minute to cycles per second, and we divide by 4 because we want 4 beats per cycle, i.e., we want one cycle to equal one traditional bar in 4/4 time.

These two values are equivalent:

• setcps 0.5625: Cycles per second, as a decimal.
• setcps (135/60/4): Cycles per second, as a fraction.

Tip

You can create a helpful function for setting the bpm, assuming a 4/4 time:

setbpm bpm = setcps (bpm/60/4)

Create global time signatures by patterning cps

You can also use cps, without set, as an effect. It’s global, so setting it on one pattern will change it everywhere.

Via patterning it, you can create quite mind-bending music where the rhythmic perception shifts for all musical layers.

A mild example would be to create a waltz-like feel by making a pattern of two numbers where the second is the double of the first:

d1 $ n "2 0 [3 5] [4 1]" # sound "808"

d2 $ s "808bd(3,8) 808bd:2*8"
  # squiz 5
  # cps "0.5 1"

But you can really mess with time in this way!

d2 $ n "0 [~ 1] 2*2 3 4*3 5 ~ 7" # sound "drumtraks"
    # cut 1
    # cps "<0.5 2> [1 0.75] <2 1>"