Extent of sound manipulation capabilities?

I'm looking into Flash to try to create a simple audio editing environment. I've seen a few "DJ" sites where you can put together premade loops of music that overlap, and I know that you can control volume of sounds.

What I would be trying to do mainly is control the octave/pitch of a sound without having to use multiple samples. Is this possible with any Actionscript sound library? I've never seen it done and Google isn't much help here. Also, would it be possible to control the SPEED of audio playback? I'd be very curious about that. Maybe if the sound were streaming in a movieclip and the speed of the movieclip were changed? I'd love to hear any ideas about this.

ActionScript controls the volume, pan and start time of a sound. Pitch change is not supported.