I have yet to properly quit a band. I auditioned for a number of bands and ended up never joining them to begin with and I was fired from a few others. However, there is one band that comes to mind. I didn't quit this one either but I sort of made myself scarce and they stopped contacting me

This needs a bit of explanation since I still laugh over this band even now.
I had been fighting depression for a year and been writing my own songs in my spare time. After a long wait of trying to put a band together, I realised I just wasn't well-known enough to convince others to play my songs so I decided to join a band. I saw a post by a band on FB and messaged them. Their guitarist met me up for a chat and we ended up talking for over an hour. I was interested so he sent me tabs of some songs they had been working on to practice for rehearsal.
Now the songs he sent me had all sorts of funny rhythms going. No problem there since I don't have any trouble with odd time signatures so I make up my bass parts and it's off to the races right? Umm, not quite. The drummer showed up unprepared and when I say unprepared, I mean he hadn't even listened to the tabs. There was a second guitarist who was equally unprepared. Later on, I was told the second guitarist was actually meant to play bass but since I joined, he was moved to second guitar which was wholly unnecessary for the music they were playing. Eventually he was fired so no trouble there. The singer didn't sing even one note throughout rehearsal. He just kept telling the drummer and second guitarist how the riffs went and what not. Meanwhile, I was getting bored because I figured everyone would show up ready but the drummer was learning the riffs on the spot. He finally managed to get it together and we played like two riffs as a band. Ok, no harm no foul, it is agreed that everyone shows up ready for next rehearsal and we go our separate ways.
I asked the guitarist why the singer never sang and he told me the singer never did sing

He also said he was extremely slow when it came to writing lyrics and even after he was done, he would replace words with other words of the same meaning using a thesaurus

I said if this was the case, I could write the lyrics instead because I didn't need a month to finish a song! The guitarist was cool with this. I also asked him if the band could try playing one of the songs I had composed because they only had like one and a half songs on their own. He told me the singer would need to sign off on that since he was apparently not too fond of singing other people's songs. I emailed both of them and the singer replied saying they were not interested in playing my songs since they had a lot of their own songs and my contributions would be limited to working within that framework. I was a bit disappointed but I still liked what they were doing so I stayed.
Fast forward to the second rehearsal and the guitarist sends out the tabs again. Only this time, the song is in Drop C instead of Drop D. When I asked him the reason for the change, he said his brother had retuned his guitar to Drop C so he was too lazy to tune it back and just worked in C. I told him the band would sound like crap in C since neither his six string guitar nor my four string bass had heavy enough strings to pull it off without sounding like rubber bands. He assured me the band would still play in D and this was just for reference. So I learnt it in D and showed up. The singer had finally finished his lyrics and came to rehearsal saying he learnt it in C. I called BS and reminded the guitarist we had agreed to play in D. He hemmed and hawed and the singer insisted on doing it in C. I finally gave in and managed to transpose things then and there (fortunately, I hadn't used open strings). After playing in C, the singer said it sounded bad and wanted to do it in D. I wanted to strangle him then and there! After doing it in D, he agreed it sounded better that way. Of course, this was only at the tail end of the rehearsal since the drummer yet *again* showed up unprepared and was again learning things during the rehearsal. After we were done, I told them we needed to fire the drummer since he was clearly uninterested. They agreed but didn't do anything.
After that, everyone was busy for a few weeks and we didn't get together for a bit. We were still communicating over messages though. I noticed the other three members (drums, guitar, vox) who were old friends were more interested in discussing the drummer's new tattoos and other personal stuff rather than music. I went off for a week long vacation and told them I'd be out for a while. More personal stuff followed in our messaging group which I just stayed out of because I had nothing to contribute. Eventually, I kept silent for so long that the singer thought I had never come back from my vacation and removed me from the group. Oh, it was a fun ride, and I still laugh at their absurdities even now. I even have the lyrics to the first song that the singer sent everyone which are so nonsensical that it is clear the guy had no idea what the hell he was doing
To cap this off, they did end up getting a new drummer and bass player later on but I think the band has broken up now. A couple of months later, a guy called me up asking me if I'd be interested in playing bass in his band. When I asked him how he found me, it turned out he had been referred to me by the singer of this band. I was really surprised since I didn't think they remembered me but I guess I left a positive impact on them after all
