There is no reference level for music. Reference level for movies is listening with your processor set at 0db if you have calibrated your system properly with a sound level meter at 30db below reference with your receiver's test tones (75db) or 20db below reference (85db) if using an Avia test disk.
This will give you peaks of 105db at the loudest portions of the movie, and 115db from the LFE (if your sub can produce those levels). Many processors offer a bass peak limiter to protect subs that can't produce that output.
Listening at reference will allow you to hear in your home what the sound engineer intended. Whether you want to reproduce those levels in your home is a separate issue.
Regarding music, I have measured peaks at Symphony Hall, Boston of over 100db in a mid-hall position of the orchestra. Most of that energy is provided by the bass, but the rest of the orchestra can get pretty darn loud. I try and replicate those levels at home when I'm in a crazy mood and my wife's away.
