Bruce Jenner -- Saturday Night's Alright ... For a New Look

Bruce Jenner changed his look up for the Elton John concert in L.A. Saturday night.

B.J. went to the show with his son Brandon Jenner and Brandon's wife. Another random girl tagged along ... but no word on who she is ... or if it was any sort of date.

Bruce and Kris Jenner made their split official last month when Kris filed for divorce.

In case you haven't been to an Elton John concert ... that's the place you let your ponytail down.