A 9-year-old rock fan up late at a Bruce Springsteen concert had a note for his teacher if he was late for class the next day — and it was signed by The Boss himself.

Fourth-grader Xabi Glovsky and his dad Scott attended the sold-out show in Los Angeles on Tuesday and they caught Springsteen's eye with a homemade sign that said: "Bruce, I will be late to school tomorrow. Please sign my note."

After the show, Springsteen invited the pair backstage where they posed for photos. And Bruce scribbled a note for the Claremont boy's teacher.

The note said: "Dear Ms. Jackson, Xabi has been out very late rocking & rolling. Please excuse him if he is tardy."

Springsteen posted the photos and the note on his website.