Refers to any record/song whether MP3
that is not signed to a record label. Often times white label tunes will be remixes usually samples illegally to show off a track and sell it to a record company but with no information about who made it so that no one can be sued - though everybody knows who made it. The production usually includes his or her contact information on the white label.
"A tune that is not signed to any record label, though you may find later that the tune gets signed to a record label and released. There are usually limited copies of it."
"The name white label comes from the fact that most promo records used to be sent out in an unfinished state, with the label completely white. The term incorporates any record that is not a finished product, including promos, test pressings and dub plates."