The earliest widespread application of digital audio technology was in the mid-1990s, when several music libraries began providing streaming audio for recordings placed on reserve for course assignments. The focus on curricular listening assignments was a natural choice, since reserve recordings are heavily used and usually constitute a comparatively small, well-defined collection.
Streaming technology is still the most popular means of providing network delivery of reserve listening. It allows libraries to provide around-the-clock reserve listening both on campus and off, and students appreciate the convenience of being able to whenever and wherever they please.