Since it came up in the section on Homecoming, I should take a moment to talk about the small-town rock band, which is very common in some places. These are often called "garage bands" as the garage is an iconic location for small shows.
There are famous of high school bands turning into world famous acts, but most are simply students with musical interests enjoying themselves. Even so, many of these bands can be very serious about their musical careers. Some of these bands can last for years, while others may only stay together for long enough to perform at one or two gigs (shows).
Most high school bands are long-time friends who happened to have skills that lined up with each other.
Some schools (mostly those in larger cities) offer opportunities for high school bands through events like "Battle of the Bands." These are large public tryouts for school events such as Homecoming.
In small town, opportunities for gigs are far more limited. This is what leads most bands to play shows in their own homes. This is not limited to garages.
For the record: Nick Goss, my guitarist, hated the garage band aesthetic. He refused to play in a garage and probably wouldn't care for me using the term "garage band" at all.
A band that stays together long enough to write a few songs may even produce an album or two. With digital technology shrinking the equipment required for recording, small studios have popped up all over the country, allowing anyone with a few dollars a chance to cut their own record.