Rare Freddie Mercury vocals that were recorded during his original Barcelona sessions are featured on "Little Freddie Goes to School," a new song made for charity.

Vocalist Esther Trousdale is also featured on a track.

The new single, which was produced by Irish composer Stuart Leathem, arrives to help raise awareness of World AIDS Day.

Proceeds and royalties from "Little Freddie Goes to School" will benefit the Mercury Phoenix Trust, the HIV/AIDS charity established in Mercury's name.

"Little Freddie Goes to School" features vocals from Mercury's "When This Old Tired Body Wants to Sing" and "The Golden Boy."

The former was a jam Mercury recorded with longtime collaborator Mike Moran, while a version of the latter eventually appeared on 1988's Barcelona, a collaborative record with Catalan soprano, Montserrat Caballé.