Lab 10

Here’s a simplified version of the data definition we developed in class:

; a note is (make-note number number)

(define-struct note (pitch dur))

; a song is either

; - a note, or

; - (make-song-pair song song)

(define-struct song-pair (s1 s2))

1. Write down the template for this function, using the name a-song-fun.

2. Develop the song->rsound function, that turns a song into an rsound by using make-tone and rsound-append*.

3. Develop the invert-note function, that accepts a note and returns another note with the same duration and the midi note number "mirrored" around 60. So a midi note number of 72, for instance, would turn into a midi note number of 48.

4. Develop the invert-song function, that alters a song by applying invert-note to each of its notes.