loopFirst :: Pattern a -> Pattern a
loopFirst is a function that takes a pattern and loops only the first cycle of the pattern. For example, in the following code will only play the bass drum sample.
d1 $ loopFirst $ s "<<bd*4 ht*8> cp*4>"
This function combines with sometimes to insert events from the first cycle randomly into subsequent cycles of the pattern:
d1 $ sometimes loopFirst $ s "<<bd*4 ht*8> cp*4>"