Fans are already clamouring for Lambert to release a snippet of one of the tracks.
The alt-country and Americana maverick will take the stage at Cadogan Hall and Union Chapel.
Sommers was a guest on Drumeo's ‘For The First Time’ challenge.
The sister duo's sophomore single, 'I Tried A Ring On', will impact country radio on January 22.
Rumor has it the pair of musical masters have recently completed a special collaboration album due out later this year.
The Golden Globe winning actor teased a potential foray into country music during an intimate concert in Colorado.
