I'm using some functions from mmsystem.h, mixerOpen(), mixerGetLineInfo(), mixerGetLineControls(), etc. My goal is to toggle the master mute or line-in mute, etc. I've got this working with a SB16 card and I can toggle the Wave out mute, but it doesn't work well with by SB Live card, it reports there are only two controls on the Play Control line - CD Audio Volume and CD Audio Mute. Why do only these controls out of the hundreds on the device show up? And since these are the only functions that can do the job, how can other applications control my volumes on my SB Live card?!