import Music
import Ex

fjcanon instrument1 instrument2 music delay = (instrument1 music) ! (delay &
                            (instrument2 music))
tune = twice (e (g4 & a4 & b4 & g4))
   & twice (e (b4 & c5) & q d5)
   & twice (s (d5 & e5 & d5 & c5) & e (b4 & g4))
   & twice (e (g4 & d4) & q g4)

z = fjcanon trumpet harpsichord tune r