C Major + Bass with Impromptu

c_major_bass.scm

; C Major Chord
; By Gilberto Avalos

; You need Impromptu to run this script
; http://impromptu.moso.com.au/downloads.html
 
; Clear all
(au:clear-graph)
 
; Define piano instrument
(define piano (au:make-node "aumu" "dls " "appl"))
(au:connect-node piano 0 *au:output-node* 0)
(au:update-graph)
 
; Variables
(define initialNote 48) ; C / Do
 
; Internal Variables
(define note initialNote)
(define notes 0)
 
; Play function
(define play
   (lambda (base_note bass)
      
      ; Bass
      (if (> bass 0)
        (play-note (now) piano bass 80 15000)
      )
      
      (if (and (= notes 0) (> note base_note) )
        (set! note (+ note 1))
      )
     
      (if (= notes 2)
        (set! notes -1)
      )
    
      ; (print "Play Note" note notes)
    
      ; Play note
      (play-note (now) piano note 100 10000)
    
      (if (< notes 1)
        (set! note (+ note 4))
      )
     
      (if (= notes 1)
        (set! note (+ note 3))
      )
    
      (set! notes (+ notes 1))
   )
)

; Tone
(define tone 0)
 
; Loop function
(define loop
  (lambda ()
     (define bass 0)
    
    ; First tone
    (if (= tone 0)
        (set! note initialNote)
    )
    
    ; Bass 1
    (if (= tone 0)
        (set! bass (- initialNote 12))
    )
     
    ; Second tone
    (if (= tone 3)
        (set! note (+ initialNote 2))
    )
    
    ; Bass 2
    (if (= tone 3)
        (set! bass (- (+ initialNote 4) 12))
    )
     
    ; Third tone
    (if (= tone 6)
        (set! note (+ initialNote 7))
    )
     
    ; Bass 3
    (if (= tone 6)
        (set! bass (- (+ initialNote 7) 12))
    )
     
    ; Call Play 
    (play note bass)
    
    ; Increase tone
    (set! tone (+ tone 1))
     
    ; Reset tone to 0
    (if (= tone 9)
        (set! tone 0)
    )
     
    ; Calling loop again
    (callback (+ (now) (* 0.20 *second*)) loop )
 
  )
)
 
; Call loop
(loop)

I don't know why I can't evaluate multiple sentences in the same IF statement.