Frank Black is not related to Jack Black or Tenacious D member, Kyle Gass. He is/was the singer of a band you saw on MTV (prompting you to buy the album, Doolittle, only to discover that none of the other songs sounded like the one you enjoyed).
Way back when, in a time when the only cool music came from British musicians...
Okay, not that far back.
...there was just another band out of Boston...
Not these guys.
...called the Pixies.
Yes, officer. That's them.
The lead-singer of the band went by the name Black Francis. After a few years and several albums (only one you've probably heard of)...
...Francis got tired of everybody else's shit (but mostly Kim Deal) and decided to break up the band without telling anyone. To avoid any awkward conversations and to keep from having to explain his moodiness, Francis changed his name (again) to Frank Black.
Needing a creative outlet to vent his moody tendencies, Frank released a solo album with a real catchy title.
It wasn't so much of a solo album as it was an excuse to ditch the annoying bass player and the drummer who thinks a magician makes a good opening act.
Frank kept the guitarist (his college buddy, Joey Santiago) mostly so he could continue using Spanish in his lyrics without having to pay a translator. When Frank finally learned enough Spanish to write lyrics on his own, he got a new band called the Catholics. They may or may not have released a few albums to critical acclaim (but commercial failure).
Even though they were part of the most influential band nobody's ever heard of, the other members of the Pixies begged Frank to come back and get the gravy train rolling again. In 2004 Frank gave in and changed his name back to Black Francis. They went on tour and made millions from people looking to relive parts of their lives obscured by drug use and those who were too young and sober to see them the first time around (thereby solidifying their hipster credentials).