In his fascinating book Capturing Sound, How Technology has Changed Music author Mark Katz describes what he calls "Phonograph Effects". A Phonograph Effect, in short, is a manifestation of how recording technology has changed music. The roughly three minute playing time of a 78 rpm record, for instance, had a profound influence on the structure of early pop and jazz music. To most audiophiles the proposition that recording (and in our case playback) technology influences how music is not only consumed but produced will not likely come as any great revelation. Katz's analysis of phonograph effects, however, from the rapid evolution of vibrato in turn of the century classical music, right through his examination of the turntable as a musical instrument in hip-hop and DJ culture, is consistently insightful and absorbing. As the book's early chapters explain, the introduction of the phonograph represented a seismic shift in the way people consumed music. Hearing an orchestra perform a symphony for instance, what was once a special privilege of an elite class, filtered down to the masses; something that was ephemeral (a live performance) became repeatable, reproducible and aggressively commoditized; record players gradually replaced pianos in the parlours of homes all over the world; in short order recordings became by far the dominant means by which people consumed music. 
If the 20th century was about recorded music's dominance, the 21st will be characterized by its ubiquity. From the vantage point of 2006 it's hard to believe that a little over one hundred years ago music couldn't exist unless you were making it yourself, or in the physical presence of someone who was. And then it was gone, never to be heard the same way again (with the possible exception of the player piano). Today, between portable players, car audio, and the garbage we're assaulted with in public spaces (ie shops, airports etc), let alone the home stereo, music is nearly inescapable.
Now that we've entered the era of file-based recordings and commercial music has been divorced from necessity of a physical carrier, a whole new range of Phonograph Effects (now perhaps better described as Ipod Effects) is emerging; another topic Katz covers in the latter chapters of his book. With CD sales waning, the notion of the album, which itself only rose to prominence with the LP, is rapidly being eroded by the resurgence of singles, now downloaded (legally and illegally) from the internet rather than stamped into 45s. Loading singles into playlists is, for many, creating a far more randomized listening experience, where rather than hearing a collection of songs released at the same time by the same artist ordered in a particular way for maximum impact, we're sampling one song at a time without always knowing what's coming next. Get enough tracks in a playlist and it's very much like having your own personal radio station, minus the advertising and (usually) inane chatter. This, as you would expect for technology still in its infancy, is just the beginning. The big changes are still to come.
Catching up with this new reality is putting the major record companies through rather unsightly public dry-heaves of panic and convulsions of misguided litigation. Hardware companies, however, are starting to figure it out. Clearly Apple has done a little more than just figure it out and pretty much owns the portable music player market, not to mention the legitimate online music business (over one billion song downloads and counting). But things at home are a little more complicated. We have yet to see a file-based music player for home systems that can rival the Ipod in terms of cutting-edge design and user-friendliness and, in so doing, mount a significant assault on entrenched CD/DVD players. That is until now.
http://www.audio-ideas.com/reviews/digital-sources/sonos.html
