Steve's Garage
I joined Steve's Garage without really trying, I was friends with the keyboard player's wife in my cycling club. I received an invite to come over and jam one time, and then again the next week, and then just was in the band. It was a lot of fun, and we indeed did practice in a garage, but in Jeremy's garage (Jeremy was Steve's neighbor).
My tenure in this band ended in a similar non-specified way. At a band meeting I mentioned my intent to get back to some more jazz. After that, we didn't have rehearsal for a fairly long while. Then one day at work, I received a group email from the band that addressed some guy I didn't know, and listed the songs he'd be playing the solos on. Those were the songs I played the solos on. So apparently, the sender hadn't noticed that I was on the receiver list. And that's how I learned that I was no longer in this band. ¯\_(ツ)_/¯