NEW YORK (AFP) - Leading US radio stations will on Wednesday simultaneously play Prince's ballad Nothing Compares 2 U in a memorial over the airwaves to the late pop legend.

The Current, a Minnesota public radio station that has long been a leading news source on the music star and hometown hero, spearheaded the simulcast which will take place at 5.07pm local time.

The timing comes from the opening lyric to the 1985 heartache song - "It's been seven hours and 13 days since you took your love away" - corresponding to the period since the 57-year-old superstar unexpectedly died on April 21.

The Current, also known by its call letters KCMP, encouraged fans to share tributes over social media at the time with the hashtag #NothingCompares2U.

"We hope that wherever Prince fans are, and whatever radio station they are listening to, they will take a minute to listen and remember his musical genius and artistry," programme director Jim McGuinn wrote on the station's blog.

He said that a number of major radio stations would join in playing Nothing Compares 2 U including Seattle's KEXP-FM, a top taste-maker in indie rock circles.

KEXP-FM plans a full four-hour Prince broadcast on Friday led by its host Kevin Cole, who was close to Prince during his rise to fame and served as the DJ at many of his parties around Minneapolis and adjacent St Paul.

Cole has said that Prince, who was famously prolific and left vaults worth of unreleased material, would sometimes give him new songs to test out on unsuspecting audiences at parties.

The timing of the KEXP tribute is also linked to Nothing Compares 2 U. The song is better known through its 1990 version by Sinead O'Connor, who changed the first line to "seven hours and 15 days."