John Making Beautiful Music...With Benji?

After spending the night of his 31st birthday celebration with Jennifer Aniston, the love birds went their separate ways.

Jen went to talk to kids at the Cahuenga Elementary School (the school invites one actor to speak there every month), but it was back to work for John, who headed to The Village recording studio.

Think he's recording another "Your Body is a Wonderland" style tribute to Jen?

Photogs also spotted Benji Madden entering the studio with his guitar, where John helped Benji pen a sappy love song to Paris. Actually we're not sure WHAT they were doing there together, but we like to imagine Good Charlotte coming out with a Paris song soon.

We've got more pix, vid and deets on the rest of Jen and John's day (and night together!) coming soon, so stay tuned!