He reports: "Big Mama Thornton is responsible - I played one of her tracks on my radio show, heard a nice harmonica solo and checked the liner notes to see who it was. It was Big Mama! It was the first time I recall hearing a woman playing blues harp, and it set the wheels turning in my head."

He set up the website Hermonicas.com to chart his progress, until the concept of a compilation record was suggested. "It's taken a few years - working with 30-plus artists can get very complicated," says Smith. "But finally the album is finished and is about to become a unique part of music history.