The collaborations discussed in this episode:• When Eric Clapton was brought in by The Beatles...• When the legendary backup singer Merry Clayton was brought in by The Rolling Stones...• When Duane Allman took Wilson Pickett to the next level and birthed Southern Rock...• When Stevie Wonder created a signature sound on the harmonica...• When Jeff Beck joined Jon Bon Jovi...• When Adam Duritz and Mike Campbell helped Jakob Dylan...• When Elvis Costello helped Squeeze with a hit song...• When Eddie Van Halen answered the call from MJ and Quincy Jones...