Listened to, but not heard.

Muzak is everywhere. Founded in the 1920's by General George Squier, the Muzak Corporation (from 'Music' + 'Kodak') boasts an excess of 80 million (admittedly captive) listeners -- making Muzak by far the most listened-to music provider in the world.

Restrictive licensing created a niche for Muzak -- and it's flourished. You're very familiar with this warning, I'm sure:

This audio recording is for home use only. It is not licensed for any other use. All other rights reserved. Any public performance, copying or other use is strictly prohibited. Duplication in whole or in part of this audio recording is prohibited.
This means that an individual can't play their own CDs in a commercial building -- that's considered a 'public performance' and carries with it a hefty fine. Similarly, playing the radio is a no-no. Enter the Muzak Corporation.

The Muzak library contains over 5000 recordings and is growing by roughly 1000 a year. Muzak employs approximately 2000 individuals and has 250,000 subscribers. For a fee, Muzak will supply a business or organization with audio recordings (on monthly CDs or streamed right into the building via the FM band or digital satellite, according to Stavr0).

Muzak offers sixteen 'channels', fifteen of which provide original artist recordings -- only the sixteenth (the 'Environmental Channel') sounds like what one would expect from Muzak: Retooled popular music, minus the vocals and harsh instrumentals. Designed to counter the ups and downs experienced by the average worker, Muzak is produced in fifteen-minute blocks with each block culminating in a minor climax. Current Muzak is subtle enough that, for many shoppers, 'Oh my God, they're playing Muzak' never comes to mind.


Muzak Corporate Site:

The Straight Dope