"The Main Monkey Business" is an instrumental from Rush

Rush (band)

Rush is a Canadian rock band formed in August 1968, in the Willowdale neighbourhood of Toronto, Ontario. The band is composed of bassist, keyboardist, and lead vocalist Geddy Lee, guitarist Alex Lifeson, and drummer and lyricist Neil Peart...

's 2007 album Snakes & Arrows

Snakes & Arrows

Snakes & Arrows is the 18th full-length studio album by the Canadian rock band Rush. Co-produced by Nick Raskulinecz, it is Rush's first studio outing since 2004's Feedback, and their first complete studio album since Vapor Trails in 2002...

. It clocks in at 6 minutes and 1 second, making it Rush's second longest instrumental, the longest being La Villa Strangiato. Drummer Neil Peart

Neil Peart

Neil Ellwood Peart , OC, is a Canadian musician and author. He is the drummer for the rock band Rush.Peart grew up in Port Dalhousie, Ontario . During adolescence, he floated from regional band to regional band in pursuit of a career as a full-time drummer...

 remarked that it took him three days to learn the song.

In a recent interview on HDNET , Alex Lifeson

Alex Lifeson

Aleksandar Živojinović, OC, better known by his stage name Alex Lifeson, is a second generation Serbian-Canadian musician, best known as the guitarist of the Canadian rock band Rush. In the summer of 1968, Lifeson founded the band that would become Rush with friend, drummer John Rutsey...

 and Geddy Lee

Geddy Lee

Gary Lee Weinrib, OC, better known as Geddy Lee , is a Canadian musician, best known as the lead vocalist, bassist, and keyboardist for the Canadian rock group Rush...

stated that the song found on the CD is a toned-down version of the original one. They referred to the original version as "crazy".

Background

The title of the song comes from a phrase Lee's mother used to describe someone up to no good: