timming slides to music?

1. Is there a way to play the music in the timeline so you could
time when you wanted to push the next slide to a specific beat in
the music. I see the green graphic showing the music track but I
cant hear it in timeline mode to slide those neat little transitions
and slide changes.

2. Can a portion of a song be played for slides 1-10 and then fade
out and a new song starts for 11-20? Right now it has to play the
whole song and then start the second.

Thanks!