Would “listen with the girl” also be an acceptable translation for éisteacht leis an gcailín?
Do you mean "to listen alongside", as in "I listen to the music with my girlfriend", meaning that we are both listening to it together?
Otherwise I'm not sure exactly what "to listen with" means in English.
Éistim leis an gceol i dteannta mo chailín
= (Literally) I listen with/to the music in/with my girlfriend's support
= I listen to the music with my girlfriend.