Music slideshow on mac

I had a program on pc a few years back called Pinnacle Studio which had a very good feature whereby you simply loaded your photos in and then added a music track and using smart movie it automatically arranged the photos to change to the beat of the music, without any tedious manual editing. Is there anything like this on the mac.

You can do it in iMovie, or there's a program called Fotomagico, that lets you do that and a whole lot more.

Does iMovie automatically arrange the photos to change to the beat though? If so how as mine just seems to set each photo to a default time of say 2 seconds unless I manually change each one?

Not not automatically as far as I know. I haven't played with it much though. Fotomagico came with Toast when I got it, so I use that when I do this kind of thing.
That said, I haven't tried doing what you asked in that either! There is a trial version if you want to have a look:

http://www.boinx.com/fotomagico/overview/