Slides not compressing to fit duration of 3 songs in slideshow. Help!

I’ve placed three songs in a row for the slideshow of images I’m making. I’ve gone under ‘SLIDESHOW’, ‘MATCH’, and ‘SLIDE DURATIONS TO AUDIO’, but still the slides far exceed the amount of music there is. Nothing about them seems to shorten, compress, or otherwise FIT the music. I’ve tried highlighting them all, highlighting only certain ones, and highlighting none while I attempt to match the slides to the music but nothing works. My only choice seems to be looping the last song in order to cover the ground of the photos.