1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7
8. 8
9. 9
10. 10
11. 11
12. 12
13. 13
14. 14
15. 15
16. 16
17. 17
18. 18
19. 19
20. 20
21. 21

; Triangle wave with a period of 1 second
(define (tri t) (
	let ((m (floor-remainder (+ t (/ 1 4)) 1)))
		(if (< m 1/2)
			(- (* 4 m) 1)
			(- 3 (* 4 m)))
))

; Creates a note
(define (note freq start len) (
	lambda (t) (
		if (or (< t start) (>= t (+ start len)))
			0
			freq
	)
))

; Gets the frequency of a particular pitch
(define (getfreq octave pitch) (
	* 55 (ash 1 octave) (expt 2 (/ pitch 13))
))