"Mumbo" is the opening track of Wings' debut album, Wild Life
. In an attempt to capture the spontaneity of live performances, five of the record's eight songs were first takes by the band, including this one.
"That song came from, you know, the band would just get an idea of a chord, or something," McCartney recalled in an interview on his website
. "We'd just jam on it. And, it would be just, 'Okay, this is in F', or whatever key it's in. And we'd just play. And I'd sort of shout stuff over the top. It's all part of becoming a band. You know, you learn that I'm gonna be goofy and sing some goofy things."