That’s more what I was wondering; it’s extremely common for all the members of a particular band to have known each other from childhood, but how many famous musicians actually grew up together and did not actually go into a band together or perform together?
Frank Zappa and Captain Beefheart went to high school together and met when they were around 16. Though they played together in high school, they went their separate ways and formed separate bands. Later, they worked together.