Takes all the available patterns, given a beat_length, ex 1/4=4 beats in a measure, so 2^4 patterns.;
Allows the user to select the pattern, via scaled hslider.;
Converts that value to binary.;
Then, on the metro, if the value at that idx (via list-idx) (as tabulated by a running counter for the total number of beats) ==1, sends the bang.;
note: rnd_pat changes the value only, i.e. not the hslider.
5:rnd_pat(any input triggers it)
p.s. used this last night on a drum-Meta-pattern generator/sample-player last night, and it made some really cool sounds.