The guitarist first worked with Ellis on 2010's Anthems, and the odd couple has teamed up for joint tours every winter, while May is taking a break from Queen.
The duo was forced to scrap their Christmas Candlelight Tour in December (16), after May announced he was "battling with a persistent illness which is destroying my energy and my will", but now he's working on new material with his muse, a West End theatre star.
They will release Golden Days in April (17)
"This album is a true collaboration between Kerry and myself," May says in a press release. "Five years ago, Anthems was the result of me producing an exciting new artist... This new record has both our names on it, and breaks new ground. We produced ourselves together as a team. I feel confident it's the best thing we've ever done and a worthy testament to 13 years of belief. It also happens to feature Britain's most beautiful voice!"