Question: "Glassheart" is a song conceptualised by Leona Lewis and a frequent collaborator who is the lead vocalist for what pop rock band?
Sentence (from "Listen (David Guetta album)"): , Bebe Rexha, South African male choral group Ladysmith Black Mambazo, Ms. Dynamite, Elliphant, Birdy, Jaymes Young, Sonny Wilson, Vassy, and Skylar Grey.
Relevant evidence: No