clutch
From TidalCycles userbase
Type: clutch :: Time -> [Pattern a] -> Pattern a
clutch degrades the current pattern while undegrading the next. The argument provided to `clutch` is the ID of the pattern that `clutch` creates or the pattern that `clutch` is replacing.
This is like xfade but not by gain of samples but by randomly removing events from the current pattern and slowly adding back in missing events from the next one.
d1 $ sound "bd(3,8)"
clutch 1 $ sound "[hh*4, odx(3,8)]"
clutch takes two cycles for the transition, essentially this is clutchIn 2.