compress :: (Time, Time) -> Pattern a -> Pattern a
compress takes a pattern and squeezes it within the specified time span (i.e. the 'arc'). The new resulting pattern is a sped up version of the original.
d1 $ compress (1/4, 3/4) $ n (run 4) # s "arpy"
It differs from zoom in that it preserves the original pattern but it speeds up its events so to match with the new time period.