For instance, I don't play "Loveshack" by the B-52's because it references sex (and pregnancy?) in a shack in the woods (in my college hometown nonetheless!).
There are A LOT of songs that you would think you could play, but on second (safe) thought, you should probably not play.
Mostly, I keep it to a lot of Beatles and late fifties/early sixties music. I like that music, and the kids don't seem to mind. I've taught in a lot of diverse environments and here is what I have learned: People have a lot of opinions on music and what they like. . . But, I've never once -in any environment- I had a complaint about the Bill Withers, the Beatles or the Indigo Girls (appropriate non-cussing songs only).
One important thing is to avoid asking students their opinions about the music. It encourages the students to ask (badger) you to play their favorites. Which, incidentally, are almost always inappropriate for school and then leads to said student attempting to share the rude lyrics of said song with the whole class. Ahem. Instead, I play what I play and they can like it or I can turn it off. It sounds a little mercenary, but I remind them that listening to music is a privilege and they can either be polite, or I can turn it off. They always decide to keep it on. :)
Having said all of the above, the most important thing I have learned is what type of TEMPO to play. As much as I love music -all types- the up tempo music gets the kids moving and grooving (great if they are in P.E. class), which is not always so conducive to working on your art project.
I began to seriously play classical music this year, and it has made HUGE difference for my classroom management. I had an entire class of kindergartner's working silently(!) of their own accord today while Debussy played. I never asked for silence (I try to never do that because I think it really limits their creativity); they just did it! Wow. I will say that I play calm classical and avoid any dramatic operas. Well, and I avoid most of Tchaikovsky because he is just so "thunder" and "lightening."
Here is what I like to play:
Lacrimosa by Mozart
Nocturne No. 2 in C Sharp Minor by Chopin
Claire de Lune by Debussy
Un Sospiro by Liszt
Waltz in A Flat by Brahms
Traumerai by Schumann
Piana Concerto No. 1 by Tchaikovsky
Petite Suite: En Bateau Debussy
Eine Kleine Nachtmusik by Mozart
The Swan (Carnival of the Animals) by Saint-Saens
Requiem - in Paradisum by Faure
Love Theme from Romeo and Juliet by Mancini (not classical, but I love it!)
I like the current mix I use so much I made a playlist to share with you. What type of music do you play in your classroom?