What do you think of this idea.

So one day I was playing ping pong with a friend and while we were playing I took out my iPhone and turned on some music. The only problem is the iPhone alone is very quite when its up against general noises of a household and you can't hear the music that well. And then I saw my friends iPhone on the table by mine and came up with the idea for the app. So what the app does is it allows friends to connect multiple iPhones together and when one of the iPhones starts playing music it plays that song through all the iPhones connected in perfect sync. So it basically uses other iPhones as extra speakers to amplify the sounds. What do you guys think?