Pearl Jam came up with their band’s name because “pearl” sounded good and Neil Young likes to “jam”.
This factual origin is much less interesting than the explanation lead singer Eddie Vedder gave in a 1991 interview with Rolling Stone magazine. At that time Vedder claimed that his great-grandfather was Native-American and culturally into hallucinogens like peyote. Vedder's great-grandmother Pearl would make preserves (similar to jam) laced with the hallucinogens. Essentially this means Pearl jam was hallucinogenic preserves.
15 year later, in another Rolling Stone interview, Vedder admitted that his great-grandmother’s name really was Pearl, but the rest of the story was totally false.
The real origin of Pearl Jam’s band name is rather pedestrian. They were brainstorming over potential band names and decided they liked “pearl” but weren’t sure about the rest. After attending a Neil Young concert they added the word “jam”. Young’s concerts are known for extensive jamming (adding extra parts to a song that are mostly improvisational but meld with the song’s musical theme).
For a brief time before using the name Pearl Jam, the band was called Mookie Blaylock. This was the name of an NBA player with the New Jersey Nets. Copyright concerns forced the band to come up with something else. They still paid tribute to Blaylock with their debut album Ten. Blaylock’s jersey number was 10.
Pearl Jam is among the performers scheduled to take the stage at the Made In America music festival Jay-Z is organizing - to be held in Philadelphia in September.