Is it possible to play multiple videos in sync?

I need to build a website which shows multiple instruments in a band, being played in sync.  Each camera/video block is a different instrument, and played together, they constitute an entire band.  I have been searching high and low for ways to do this, and it definitely appears that HTML5 is out.  It looks like standard FLV progressive download is out, too, because it's impossible to get 4-8 videos to sync perfectly.

I see on the FMS page that it has some abilities in synching.  How would one (conceptually) go about making a webpage where say 4-8 videos begin to buffer, then when ready, play in sync?  And they would also need to, when the location is changed, all sync to that location and rebuffer. 

The objective is so that the user can mute/solo each video's audio, to remove an instrument(s) from the "mix" at any time.

An alternative way of doing this, I think, would be to just put the 4-8 videos together in video editing, and encode this into one video, but have each video's audio track be a separate audio channel.  If FMS can do multichannel audio on one video, this might work, if it could mix them in/out individually, as the user requires.

Any insights on this problem would be greatly, greatly appreciated. 

Thanks!