Preposition for singing and guitar

Question

If someone is playing songs on the guitar and people are singing songs related to that playing, how do you say it most naturally?

1. We are singing songs to the guitar?
2. We are singing songs under the guitar?
3. We are singing songs with the guitar?
4. We are singing songs while someone plays the guitar?

Answer 1

A reasonable set of phrases is:

1. We are singing songs to the guitar.
2. We are singing songs accompanied by the guitar.
3. We are singing songs along with the guitar.