This wasn't necessarily hacked: the Macintosh 3.5" drives were variable speed drives - they'd turn the disk slower when accessing the outer tracks so that more data could be written to a single disk (400kB as opposed to 240kB!). In fact, there was even a shareware program for the Mac 128k through the Plus back in the '80s that did exactly what the quote describes - played a variety of songs on the internal drive.

-matt