As I'm now a teen librarian assisting with a teen tech lab that includes some musical stuff, I and a coworker are experimenting with guitar in there. We've both been playing occasionally during children's storytimes. What I'm seriously considering for next month is family-friendly folksongs appropriate for the holidays that could be thrown into the programming we're already doing, either for teens or family groups. I'm still a beginner, mostly stuck on A, D,and G chords atm. My coworker, however, has taught guitar and also knows some piano.

Labor Day:

A few Pete Seeger and Woody Guthrie songs come to mind. I've recently learned The Work of the Weavers, and am thinking about Gonna Be an Engineer. I've posted the former on Youtube, but have never really noticed links posted here, so not sure if it's permitted. The latter would be really appropriate for promoting STEM.

Hispanic Heritage Month/Mexican Independence Day:

No idea, really; some of my coworkers probably know a song or two.

Talk Like a Pirate Day:

Any number of public-domain sea songs -- "The Fish of the Sea" and "Rhyme of the Chivalrous Shark" are humorous ones that might go over well with the kids I work with. "15 Men on a Dead Man's Chest" might be good. I like the Pirate's Serenade, but I'm not sure it would appeal to kids.