Fade audio at slide end

I have a 17 minute presentation, consisting of multiple slides and videos, with an extended song in the background. The song is too long, and I cannot fade the music at the end.
I do not want to match the slides to the length of the song.
I have a Scree Shot, but not sure how to post it

I solved the problem, by deleting the extended song, and re-importing it twice, instead of dragging the end to extend it. I did some editing, so the trasition was not noticable.
The song fades as wanted desired, I just wish I could figure out how to keep the the ending slide on screen, like I can do with FinalCut Pro X.