Re: "I'll stick to FCP but I encourage you to switch to CS6"

[Giorgio Palazzi] "It was when I tried to lock myself to music FCPX felt like a cold bath."

FCP X tries to keep most things in "local sync", such as sound effects with the clip they were attached to. This falls apart with a music video, where "global sync" is more important, and you may not want everything to ripple.

Still, it's pretty easy. Add your music track as the Primary Storyline, and connect clips to it. If you want more typical FCP X rearranging abilities, select some/all of those connected clips and make them into a Secondary Storyline with Command-G. Connect all your edits (or drag them into that secondary storyline) and you'll be fine.

Another way is to connect the music track to your first clip, then activate the Position tool to avoid rippling.