Johnny Depp crashed Willie Nelson’s show in Boston on Tuesday–and some audience members didn’t even know it. Depp, who is in Boston filming a movie about mobster Whitey Bulger–in which he plays the lead character–simply played guitar throughout Nelson’s set. The 81-year-old (yes, Willie Nelson is 81) introduced his band members, but used only their first names.

“He just said something like, ‘And that’s Johnny over there playin’ the guitar,’ ” an attendee from Boston said, adding that Depp “even played a solo in one of the songs.”

Can you imagine how exciting this must have been for those in the audience who realized exactly who the handsome guitarist was? It’s like they got a ‘two-fer’ at a Willie Nelson concert.

The fans who did recognize Depp eagerly shared their discoveries via Twitter.

WOOOOOOOO#!!!! JOHNNY DEPP & WILLIE NELSON RIGHT NOW! SOOO HAPPY!! pic.twitter.com/0ftN2jlOFi

— Sunshine (@MsDWright) June 18, 2014

Johnny depp in boston playing for willie Nelson pic.twitter.com/a9QeyU8UMR

— Country StandardTime (@countryst) June 18, 2014

Surreal seeing Willie Nelson play in Boston tonight. Then we realized Johnny Depp was on stage incognito playing guitar w/him. Mind blown.

— Rick Riordan (@camphalfblood) June 18, 2014

Johnny Depp last night with Willie Nelson (Boston) pic.twitter.com/KofrmnVuwh

— ☮ (@IndoDepp) June 18, 2014

Just a few hours earlier Johnny Depp appeared on the set of Black Mass along with costar Juno Temple, as they filmed scenes in South Boston. Fiancee Amber Heard reportedly watched some of the filming this week. It’s unknown if she is sticking around or had been in town for long. Depp turned 51 back on June 9th. Perhaps her presence was an ongoing birthday treat?

Johnny Depp is unrecognizable in makeup and in character as Whitey Bulger in the biopic. One would never recognize the mobster as the man who played guitar on stage with Willie Nelson. His slicked back hair worn over a bald cap is a major transformation from the heartthrob women have lusted over for years. The film is based on the 2012 nonfiction account of Bulger’s crimes–also titled Black Mass.

The real Whitey Bulger is currently serving two consecutive life sentences for his crimes. The film is set to premiere in theaters some time in 2015.

Image via YouTube