According to Gene Koprowski of Tech World News "digital downloads have replaced the single and iPods are the new turntables". For a somewhat interesting if narrow perspective of the music industry through a techie's eyes check it out.
"...because of digital downloading technology and the Internet, the single is making a smashing comeback. For example, a wacky song called "Laffy Taffy" by the Atlanta rap group D4L was first thought to be a novelty song, and nothing more, by music producers.
It turns out, however, that the song has been downloaded -- for a fee -- more than 700,000 times from iTunes, Yahoo Music and other online music stores..."