Hello!

So my question is pretty simple.
I shot a video of myself playing drums while recording a song.
While waiting for the final mix of the song to be done, I wanted to prepare a website, to feature the recording and where people can watch me play.
The one cool thing I want to do, is to have the song playing, and while it's playing, the viewer could choose between the two cameras.
How do I do that?
I'm thinking I should place the audio in a single looped frame, and then put the two video streams in a movieclip with buttons to switch between them?
As in, both are always playing but the viewer just switches, like as in viewing different frames?
Also, what's the best way to have the site detect whether the viewer is using a smartphone and then switch to the smartphone version?