Piano & A Microphone is compiled from a 1983 home studio cassette of the late musician playing jazz piano versions of some of his own songs and those of others, record company Warner Bros said.

Prince, 57, died of an accidental overdose of the opioid fentanyl in 2016, leaving behind thousands of recordings and videos in the vaults of his home studio in suburban Minneapolis.

The new video, shot recently in New York City, accompanies the album track Mary Don't You Weep, a 19th century spiritual.

It is intended to pay tribute to the hundreds of people who are killed or wounded by gun violence in the United States, the record company and the singer's estate said in a statement.

Prince in 2015 performed at a Rally 4 Peace concert in Baltimore following the death of Freddie Gray from injuries suffered in police custody.

The Mary Don't You Weep video begins with a quote the musician made at that rally, "The system is broke. It's going to take young people to fix it."

Piano & A Microphone hears Prince working through his songs Purple Rain and 17 Days, as well as a version of Joni Mitchell's A Case of You.

It is one of a handful of recordings released posthumously by Prince's estate, including an expanded edition of his Purple Rain album and Anthology: 1995-2010, a selection of 37 of his biggest hits.

Australian Associated Press