Using photos & music in slideshows

I have a number of photos I want to make into a slideshow from a team building event, using either iPhoto or keynotes. I want to be able to assign a number of songs throughout the slideshow e.g. 1 song for the first 5 slides to fade in and out, then a different song for slide 5 - 12, and so on. Can anyone tell me if this is possible in these software apps, or would I better using something else?