If you’re on Catalina and, you just installed the latest Security Update from Apple, released Dec. 15, 2020, you’ll notice now that the iconic “startup chime” has changed:
It seemed initially these new sounds were only for Big Sur, but the startup chime has been ported to machines running the latest Catalina install. And the change is permanent; it’s been altered in the mainboard firmware chip, no matter what OS you boot into.
When this happened to me I thought, “Oh god, hardware failure…” because this new chime is drastically different. (Not sure I like it.)
So don’t freak out and call Apple like I did initially; it’s just “progress”.
Happy holidays to all.