Jack White’s renowned Jay-Z collaboration, “Ray Bans,” appears to be trapped in the Hova vaults, but Third Man Records’ debut rap foray arrived tonight in the meantime: “Brain” b/w “Royal Mega” was released digitally and on 7″ vinyl, starring Detroit hip-hop artist Black Milk — who put a live album at TMR’s Nashville HQ to tape in the spring — with horn and live drum-driven co-production by Jack. Sample the B-side, “Royal Mega,” (mislabeled in SoundCloud) below or with “Brain” over at SKoA.