As the site notes, Apple treats the silent songs just like their more musical counterparts. The silent tracks sell for the same 99 cents as other songs, feature free 30-second “previews” and are all wrapped in Apple’s usual digital-rights management software to prevent unauthorized copying.”
iTMS: Get your 99 cent song of silence
“Among the hundreds of thousands of downloadable songs for sale at Apple Computer’s online music store are at least nine tracks of silence, a fact that has prompted quite a bit of discussion. The chatter over the inaudible music tracks began this week at Mac enthusiast site As The Apple Turns.