There's more to prosody than just rhyme and meter, though they are what most people think of.

Here's one exercise I've used:
Have each participant take a verse, or chorus, to a song he or she knows really, really well, both musically and lyrically, and which, MOST IMPORTANT, he or she admires for some reason. It's ok if everybody has a different fragment. Write it down (just the verse or chorus, shouldn't be more than 8 lines, and more usually 4). Then each person analyzes that fragment for rhyme scheme, meter, assonance (like vowel sounds), consonance (like consonant sounds), and interesting figures of speech (metonymy, synecdoche, metaphor). This will take awhile, depending on how well they understand what they're looking for. At the very least, this exercise will give them a deeper understanding of the components that make a lyric interesting to themselves. Then, you have a couple options if there is time left over: You could have them create a similar lyric (just 4 to 8 lines, not a whole song!) using a topic and words of their own, but using the rhyme scheme, meter, and other prosodic tools that the lyricist of their fragment used. You can also have them share what they found out about their fragments.
As with any workshop, the quality of the output will be highly variable, but the objective is to give people a close up look at the prosodic elements that interest them.

Just my $0.02, for what it's worth...your mileage may vary!

Good luck, have fun, and bless you for doing the job!!!

V