I think you're answering my question of, if you can't do it even as a quasi-financial support (meaning, say, HALF of what you feel you'd like as a household financial income), don't do it at all. For $1,800 a year to nail 300 songs in a tux and hang around all day on a weekend (to play Boogie Oogie Oogie and the like)......kinda puts the No-Go on that!
Which begs the question, if not doing it full time, how is a person, or band, expected to show up and nail it out of the blue? Like the bench player called in after sitting around for games on end. How do you expect that player to execute perfectly when they've been sitting around all season. Practice is practice, performance is performance.
It's easy, we all play with other bands regularly. That's what keeps us in shape and our chops up.
Nobody had to learn all the songs in the catalog as most of us already knew a bunch of them from playing in other bands. In the acts I work with regularly, I'm probably playing over 150 different songs anyway, so it's no big deal to me.
Everyone can read charts. Everyone knows how to learn a song quickly. We rehearse anywhere from 20-30 songs in a session, no sweat. We don't waste time, and the players appreciate that. We're more likely to play Reel Big Fish or Big Bad Voodoo Daddy than Donna Summer, and the guys have fun with that.
$1800 may not seem like alot of money, but that's the average take home for 18 bar gigs as a side man. You would have to gig twice a weekend for a 2 months to make that in the bars, while we make that in 1/3 of the amount of gigs. $300 is also the least that someone makes. If the reception pays more, or the players are doing a cocktail hour or ceremony, they'll make well over $300. In that case, a single wedding gig nets them more than playing every weekend at the bar for a month. As the BL, I have made more at a single wedding than I have with a bar band playing every weekend for a summer. I have no problem finding players, and most folks would happily replace themselves for bar gig to do a wedding. As a musician, time is our most valuable asset aside from our talent, and this band lets them make more for their time than their bar gigs (and sometimes their other wedding gigs).
For some folks, my band is a stressful gig with a lot of work. I can fully understand that. Unless you come in with a large repertoire, the necessary chops, and an ability to read and learn, it's not worth it.
For the guys in my band, it's some of the easiest money they can earn while having a fun time. If you already have the chops, large repertoire, and the ability to pick up tunes quickly, it's not overwhelming or difficult at all.
As a BL, I love being able to concentrate on the show without being concerned with filling bar stools and selling alcohol. I also appreciate there being enough margin for me to take an extra cut for booking the gig and lugging the PA.
Like I said, it's not for everybody.