Even Apple Support themselves advised me to NOT update to Catalina until further notice, and that was just a few months ago. 90% of the calls they get per day are about issues that are actually being caused by Catalina and nothing else!
I am also hoping that 10.16 will be a major fix. Maybe they'll have more time to work out bugs now! High Sierra was the last one that was half stable, and that was only after a year's worth of patches. 10.12 Sierra was actually the best one in recent memory. Mojave is okay but is kind of resource heavy on older computers IMO.
Ironically, High Sierra was much more of a "getting ready to start pushing people toward Catalina" release, and despite what Apple branded it as, it was actually LESS stable for music use than Sierra (which is running happily on the old iMac I am typing this on). I was very worried about Mojave, but by the last pass (10.14.6) it was actually very stable and nice to work with. I will be staying at 10.14.6 for a long time, simply because it's what I have on every Mac I own, and without exception, none can or should be upgraded to Catalina because they're all too old.
I see Catalina as being the first hesitant step in a path toward partial convergence with iOS, as well as laying the groundwork for a definitely-happening-and-fast-approaching move away from Intel silicon. Apple's A Series chips are kickass, and only using them in iOS devices is quite limiting, the newest iPad Pro with cursor support (GASP SHOCK HORROR!) notwithstanding. It will be a long damn time before this tech works reliably for the new hardware that's on its way, and it may never work right for the old hardware that's here right now. I would argue that despite Apple offering all sorts of backward compatibility, there is absolutely no point putting Catalina on anything that isn't based around USB-C/Thunderbolt 3. I neither have nor anticipate having such hardware for a while, so there's no point to Catalina for me. When I get to that point, I will see what's out there.
Because I am an obsessive maker of lists, here's a history of this bumpy road (with emphasis on music functionality). Note that in pretty much every case, the "canonical" OS is the last update pushed before the next one came along.
Puma - barely did music
Jaguar - CoreMIDI and CoreAudio descended in a choir of angels - I actually have a plastic iBook that runs 10.2.8 happily
Panther - shaky at the start, got good toward the end, last "prep for the next OS" update hosed it permanently
Tiger - very nice and useful for a good long while; I have a G4 Powerbook that was until recently my emergency streaming machine, that sits at 10.4.11 and works a treat
Leopard - serious issues, so serious that they started doing "fix" OSes like
Snow Leopard - which did in fact fix a lot of the crap that came in with Leopard
Lion - hork barf
Mountain Lion - an actual "fix" OS that fixed stuff! Weird, but okay. Not a bad watershed OS.
Mavericks - got good toward the end, well optimized for the stuff coming out in the Retina era
Yosemite - a train wreck
El Capitan - another actual "fix" OS that fixed stuff! What were they thinking?
Sierra - nice and stable, a good place to stop on pre-2012 hardware (which is still very useful for music)
High Sierra - skeptical hippo is skeptical
Mojave - very rocky start, quite solid by 10.14.6 - another watershed for the preconvergence era.
Catalina - FAW DOWN GO BOOM