Since 2016, Apple computers per default come with the F major startup chime disabled. This chord was not just for fun, but rather indicated a successful hardware test. To reeanble it, type the following command from an admin account on your Mac:

sudo nvram StartupMute=%00

and reboot.

Switching off the startup chime again requires

sudo nvram StartupMute=%01

and reboot again. Or press ⌥⌘PR while rebooting to reset NVRAM completely to factory defaults.