Sally O’Reilly at Cabinet Magazine:
Sonic branding is big business. Should you be interested, you could commission the composition of a long-form anthem, a sonic logo, or the sounds your product emits during user operation. Computer and video game companies lavish much time, effort, and money on the second and third of these. For a canonic commission, there is the Windows 95 start-up sound designed by Brian Eno. A more guerilla affair was Jim Reekes’s Apple computer start-up chime, which he snuck onto a new Mac model without permission circa 1992.13 Interestingly, the sound he was so driven to replace was “absolutely the most inharmonic dissonant sound you could make”—a tritone. There are many other, less substantiated stories out there: that one-eighth of the bits of the original Sonic the Hedgehog game were taken up by the SEGA sonic logo; that the first note in the Intel logo comprises twenty sounds, one of which is an anvil being hit; that the first Facebook messenger “ding” was an F major seventh, which comprises the pitches F, A, C, and E.