The winners and finalists of the seasons have seen varied levels of success with musical releases.
In a first for a music competition series, NBC and Universal Republic Records (later moved to Republic Records in 2012)[1] offered fans of the show the ability to vote for their favorite artists by purchasing the studio versions of the songs that they perform on the live show each week via the iTunes Store.
[2] There is generally a studio version released for every song on The Voice by its contestants, except for the Battle Rounds and the Knockout segment of the show.
However, from season two onwards, only the winner's version of the song from the battle round is released.
With the introduction of the Knockout Rounds in season three, where each contestant from the pairing sang a separate song, only the winner's single is released.