Madonna made a surprise appearance for the ages at The Abbey in West Hollywood ... and Addison Rae helped hype up the crowd. Madge performed for about 30 minutes early Sunday ...

Chet Hanks performed at Stagecoach on Saturday, and his number one fan -- his dad, Tom Hanks -- was right there in the crowd singing along!  Chet was performing with his band, ...

Can you guess who this gorgeous gal is based on her perfect bod alone?? Here's the mystery singer showing off her physique after an apparent workout sesh ... snapping the pic ...