Wale, The Highbridge Voices choir, and Metro Boomin turn a remarkable jam session into a catchy banger with their single "Voices In My Head." Mass Appeal described how the "exclusive" collaboration happened, from inception, to, experimentation, and finally a full blown song complete with a haunting beat and soulful harmonies. The most surprising part is that the whole thing works, proving that Wale and Metro have an impressive chemistry together as well. Watch the creation of the song above, and listen to the finished product below.