The Silicon Graphics O2 - their new "low-end" system introduced in 1996 to replace the aging Indy - was a graphics workstation that still managed, for its time, to pack a wallop in terms of RAM capacity, real-time 3D graphics, and CPU grunt.
While working on emulating the O2 this past weekend and looking at some scattered source code that's been floating around the web, I kept coming back to the code that generates the plucked-string boot chime, as it appeared that there were enough tables for 11 different chimes, although only 3 were used.
I wrote a small program to compile and run the relevant segment of code, generating a WAV for each table. Sure enough, in addition to the usual Power On, Shutdown, and Graphics Failure chimes, there are 8 others that vary from completely unique to barely different from the main three.