INT 80 - SoundBlaster SBFM driver - PLAY MUSIC

	BX = 0006h
	DX:AX -> music block
Return: AX = status
	    0000h successful
	    0001h music already active
SeeAlso: BX=0000h"SBFM",BX=0007h"SBFM",BX=000Ah"SBFM",INT 1A/AX=FF04h