I do share your experience, though, and always played my PAL titles in 60hz without any noticeable issue. I didn't know about the software check to adjust music timing, which explains why I thought the audio timing was independent on 50/60hz.
Is it wrong to assume that SNES handles this issue entirely by hardware (I'd assume the code just loads the entire track into memory and tells the console to initialize it, but I don't know anything about SNES hardware)? The earliest example I recall of this was then Final Fantasy 6 (III) came out and the opera would desync when playing the game here in Europe, with the music ending long before the scene. At the time I knew nothing about the 50hz issue, obviously, but I doubt Square's programmers included a check that would speed up the music on a PAL console.
It's funny though considering how many developers went all in trying to optimize their gameplay for 50hz releases on the NES from the late 80s on. Notable examples would be Tecmo, Taito, Natsume, SunSoft and of course Nintendo who did it for practically every game they released after Zelda 1. Curiously, Giants like Capcom and Konami rarely cared at all, but you would imagine that there would be a ton of developers who wanted to continue this trend on MegaDrive as well? Maybe most had just decided that it's not worth the effort at this point?
Not surprised to see high-performance machinery was a real-life interest of the graphic designer; Ranza showcases some impressive and lovingly-rendered gear.
