h-sound (:clipped #f :statistics #t :channels 4) (fmpmran 0 1 1000 .5 1))

;; FM(odd-sines-alternating-sign) = PM(sq)
(define* (fmpmodd beg dur freq amp (mc-ratio 1) (index 1.0) (phase (* 0.5 pi)))
  (let* ((start (seconds->samples beg))
         (end (+ start (seconds->samples dur)))
	 (fm-carrier (make-oscil freq))
	 (pm-carrier (make-oscil freq))
	 (fm-modulator (make-nxy1sin (* freq mc-ratio) (* 2 freq mc-ratio) 100))
	 (pm-modulator (make-square-wave (* freq mc-ratio) 1.0 phase))
	 (fm-index (hz->radia