I have no idea how experienced you are as a musician, Don, so at the risk of teaching my grandmother to suck eggs, I would like to mention that it's important to play the songs in a key that your friends are comfortable with.

Where I live (Midwest USA) most commercial songs are too high for the general public. I believe I read in a language book that Americans in general pitch their voices lower than those over the pond, and it gets to be habit. Whatever, a song that goes up to high D is going to make people here uncomfortable, and then they'll quit singing.

The leader of my church choir often asks me to take songs from the songbook and make them lower so that the congregation will sing along. Going from D to F is a typical change. (Guitars use capos.)

If you get a song for the party, consider whether it will be singable for the general public where you live. Also, keep in mind that smokers need low songs.