Los Angeles, Jul 27 (IANS): Singer John Mayer has admitted he agreed to join the cast of the thriller 'Vengeance' after he was approached by his friend B.J. Novak.

The 44-year-old musician told 'Entertainment Tonight': "I like being in my friends' movies."

"I don't really have a brain for acting. I like when my friends call me and say, 'You wanna do stuff?'"

The 'Your Body is A Wonderland' hitmaker added: "I'm my own agent for film. It happens just when friends go 'Hey I have an idea for you,' - I go 'yeah, I'll do it.' Simple as that!"

Mayer praised Novak, best known for 'The Office', and his "thoughtful" approach to filmmaking.

He said: "B.J. is very thoughtful on where he wants it to go."

The Grammy winner appears in the movie as a "parody" version of himself with very little self awareness, calling his scene "a great moment between two guys that are smart but dumb."

Mayer added: "The way we are talking it's like we are only ever listening to ourselves talk."

Meanwhile, earlier this month, the 'Get Hard' star had to cancel a Florida gig after his father "suffered a medical emergency".