If you're a famous musician, it's easy to feel like you are doing the same thing over and over. Sometimes you just need to mix it up and do something different. Play a style of music you aren't known for, or collaborate with a new group of musicians.

Of course, this can come at a cost, as the "musical side project" is often code for "pretentious, navel-gazing mediocrity." But there are some definite exceptions to this rule, which is why we're debating what belongs on the Rushmore of Musical Side Projects.

SHOW NOTES

• Traveling Wilburys (Joint Choice)
• Monsters of Folk (Michael's Choice)
• New Pornographers (Richard's Choice)
• The Glove (Michael's Choice)
• Power Station (Richard's Choice)
• Gorillaz (Michael's Choice)
• The Raconteurs (Richard's Choice)