SUBROUTINE SUBR
	COMMON /P/P(1) /PL/PL(1) /INS/ INST(27),BG(60)
	COMMON INUM,IPAR,CNT(27),BT,IREST,DF,DUR(27)
C   INUM=INST#  IPAR=PARAM#  
C   BT=BASIC TIME P1 WHEN SUBROUTINE IS CALLED
C   IF IREST IS <0, THAT NOTE WILL BE A REST.  
C   INST=INST. NAME,  BG=INSTS' BEGIN TIMES.
C   NOTE #S IN SUBROUTINE: (1-84)  C4=37  FS4=43  C5=49  ETC.
C   F1=86  F15=100 (NO F16!)

	X=P(3)
	IF(PL(3).EQ.1)GO TO 1
	X=IFIX(X)
C  FOR RAND NOTES TO LOCK ON NOTE NUMBERS.
	X=30.8677*2**(X/12)
C  X=FREQ. IN HZ. BASED ON NOTE # IN P3.

 
1	DF=P(IPAR-1)+P(IPAR)*P(4)/(X**.3333)
2	END