Controlling Sound Pitch with Flash, is that possible?

Hi everyone!
I guess that what I want to do is kind of crazy, but I would really like to control the pitch of a sound playing. For example, imagine a karaoke player. I want the user to be able to switch the pitch up or down wether the instrumental music is too low or too high for his/her voice. Is that clear?

Do you think it could be possible to do something like that? Switching the sound pitch in real-time?