I’d never heard of this: artists being covered before they release their records. From The Telegraph:

Copycat versions of popular songs have been widely available since digital downloads took off a decade ago.

The practice sees session musicians and computer experts produce a near-exact imitation of the original after hearing it on the radio. The copies are sold on websites such as iTunes and Amazon, typically for 79p a track.

Previously, however, the copies have only been released after the original version became popular.