Apple Corps v. Apple Computers

The Beatles, who had started a record label and general purpose company called Apple Corps, sued Apple Computer for trademark violation. The two companies reached a settlement and Apple Computer agreed to stick to making computers. Crucially, this included not putting their name on equipment "specifically adapted for use in the recording or reproduction of music." The Beatles sued again when Apple Computer introduced a variety of music-related computer technology, including MIDI hardware and software, which enabled computers to receive and manipulate signals from live instruments for music production. The Beatles claimed that Apple Computer had used the Apple name for musical equipment and thus violated the agreement. The two companies reached another settlement, thought it's worth noting that Apple Computer's 1991 operating software included a sound file called Sosumi ("so sue me"). These are just two episodes in a long-lasting saga of courtroom clashes between the two Apples (bring on the puns).

Interesting side note: Sesame Street aired two parodies of the Beatles' music: "Letter B" and "Hey Food." The parodies are obviously inspired by "Let It Be" (and even feature fans screaming in the background, Beatlemania style), but the chords and melody are noticeably different. That wasn't enough to stop Children's Television Workshop (the nonprofit that produced Sesame Street) from being sued by Northern Songs, a media company that had acquired the rights to the Beatles' songs after the Beatles had gone public with their publishing company. Michael Jackson bought the rights to the Beatles' music from Northern Songs in 1984 and settled with CTW, asking the Sesame Street songwriter, Christopher Serf, to pay $50. Paul McCartney later wrote Serf a letter to say that he enjoyed Serf's parodies.