Depp performed for sellout crowds alongside Beck at the Royal Albert Hall in London three nights in a row as he awaited the verdict.
And he invited his ex-girlfriend Moss to one of the shows, sources say.
Moss, who acted as a rebuttal witness in Depp's trial, took him up on the offer and was snapped leaving the venue after watching him perform covers of John Lennon, Marvin Gaye and Jimi Hendrix.
Videos of Depp playing guitar and singing show the audience cheering him on.
Johnny Depp celebrated his victory at a UK pub. Photo / Angie Jenkinson, Facebook
During the trial, Moss testified against a long-standing rumour that the actor had pushed her down a flight of stairs in the 1990s.
The supermodel became a star witness after Heard referenced the rumour.
During her brief appearance, she testified, "He never pushed me, kicked me or threw me down any stairs."
Speaking from Gloucester in England, Moss recalled how she had been leaving her hotel room at a Jamaica resort during a storm when she fell downstairs and injured herself.
Johnny Depp watches on as former girlfriend Kate Moss testifies via video link. Photo / Evelyn Hockstein, Pool via AP
"Johnny had left the room before I did, and there had been a rainstorm. And as I left the room, I slid down the stairs and hurt my back," she said.
"I screamed because I didn't know what happened to me and I was in pain," Moss testified.
"And (Depp) came running back to help me and carried me to my room and got me medical attention."
The famous duo dated each other between 1994 and 1997.
