“Mood music on record […] functioned as Muzak’s id. Muzak was confined mostly to modertate tempo arrangements with few if any distractions. But mood music indulged in volatile mood swings forbidden in the workplace: happy to grim, frantic to narcoleptic, sexy to robotic. Records abounded with outrageous themes, dissonant styles and risque suggestions.
“Still, mood music’s essential ingredient was as unmeasurable to the recording industry as ether was to radio. The common properties of mood albums? Slower, more hypnotic time signatures; massed strings treated with echo-reverberation; background vocals that sounded more angelic (or in some cases, demonic) than human; and often well-conceived philosophies about music’s utilitarian function.” 
“American supermarkets and department stores built in the 1950s were meticulously constructed, reverberant temples of alloy and glass. Their reflective surfaces (and in some cases, their curved “space-age” roofs) had proved capable of sustaining echoes as intoxicatingly as a medieval church. Of all the easy listening maestros in the Cold War landscape, Ray Conniff comes closest to furnishing music that is “to the supermarket born.” Conniff’s music connotes the mystically metallic clanking of shopping carts trailing down aisles, the rustle of cash registers, the tinkle of loose change, and the grunt of the chromium doors automatically opening for the next phallanx of shoppers. Conniff’s meticulous, up-tempo, and regimented beat has a chilly innocence – the perfect soundtrack for patrons traipsing under Safeway or A&P keliglights.” .
Joseph Lanza. Elevator Music: A Surreal History of Muzak, Easy Listening and Other Moodsong. [Revised and Expanded Edition]. Ann Arbor: University of Michigan Press. 2004.  p. 16,  p. 103.