Brain research teaches us that music helps make connections in the brain.
I play music in my classroom all the time. Sometimes I play slow, classical music to help the children focus. Other times, I play upbeat music to get the children involved. I also play seasonal music to help the children "feel the season". Here are some of my favorites:
Music for Concentration is one of my staples. It's magical background music for when the children are a little too chatty and a little less focused. I turn on this CD and they settle in and get going on their work! This series has several titles, and my goal is to own them all. I haven't tried one that didn't keep up with its promises! Here are a few others in the series:
I have these except the Music for Thinking, which is on my wishlist.
Other great background music:
I also play a good deal of upbeat music, particularly when the children arrive in the morning. It gives them the feel that the classroom is a happy place. This is some of the music I play:
Of course, kids aren't limited to music designed for kids. They get a kick out of some of this timeless music:

Then of course, here are a couple of my personal favorites:
And to think I haven't even mentioned showtunes! (My very favorite music!)
Here are some previous posts with suggestions for certain holidays:
St. Patrick's Day
Cinco de Mayo
Any Patriotic Holiday
I'm always looking for new resources. What music do you listen to in your classroom?