Originally introduced in 1991, Apple's QuickTime Player broke new ground for multimedia computing, which barely existed at the time. In 1994, QuickTime added support for music track playback that transcended existing computer audio quality and only necessitated small (now infinitesimally teensy) data files, like MIDIs, with its own native sound synthesis engine.
Over time, QuickTime grew into Apple's default video playback program, which lives on today. (For instance, you'll need it to watch Cook's keynote speech next week at Apple's Worldwide Developers Conference.)
Source: Wikimedia Commons