Soundings: is the penny dropping…?

David Bowen, internet correspondent for the Financial Times, commented on the way in which sound was being left out of the mix in the web based multi media environment. (See http://www.ft.com/cms/s/dedabc52-d3e5-11db-8889-000b5df10621.html). Implicit in his last paragraph is a warning about uninformed usage…"Music not Muzak". So what might the difference be?