Deep cut

In radio broadcasting, a deep cut or deep track is a song that is rarely played on the air. This is usually because the track was only released on an album and never as a single, or because the single never became a Top 40 hit. Most radio stations avoid playing such songs, preferring to play music that is more familiar as an easy way to gain higher ratings. However, music aficionados who grow weary of popular stations with limited playlists tend to seek out outlets that play deep cuts, in much the same way that they seek out freeform stations.