study 09 of 10

Live scripts

Every function so far ran once, when you chose it, and then finished. A live script keeps running with the sequencer: it wakes on the clock, on a MIDI note, a controller or a trig, does its work, and sleeps until the next event. This study builds a bass filter that moves on its own, then pads you play from a MIDI controller.

Waking on the clock: in clock

in clock n: runs its block every n clock ticks. A quarter note is 96 ticks, so in clock 24 is every sixteenth and in clock 96 every beat.

def wobble
  var cut 64
  in clock 96:
    cut lim add cut sub rnd 21 10 20 120
    trk 1:
      par.set fx1 2 cut

Here var matters: a live script keeps its named variables from one wake to the next, so cut walks up and down instead of starting over. par.set fx1 2 cut writes the second parameter of FX1 on track 1, the cutoff when FX1 is the filter. How a live script is started and stopped depends on your firmware.

Starting on the bar: launch

launch n makes the first wake wait for the next multiple of n ticks: launch 384 starts the script on the next bar in 4/4.

Waking on MIDI and on trigs

def pad_play
  in note 1:
    a sub note.num 59
    if and gt a 0 lt a 9:
      trk a:
        trk.level note.vel
        play a

The other direction works too: send.note, send.cc, send.prog and send.nrpn send MIDI out, from a live script or from a menu function.

Scripts that talk to each other

Live scripts can be wired like modules in a patch. gate n sends a gate on one of the script's four outputs; another script that declares in gate NAME n: wakes on it, in the same tick. out n v publishes a number on an output, and cv NAME n reads it from another script.

def acid
  in clock 24:
    prob 50: gate 1
    out 1 rnd 128

def follow
  in gate acid 1:
    trk 2:
      par.set fx1 2 cv acid 1
    play 2

What a live script may not do

A live script runs while the music plays, with no one to answer a question: it cannot use an operation that asks for confirmation, such as pat.copy. The checker refuses it, in the script and in the bricks it calls.