We knew that much of the music was going to strike a traditional note. The music for the long, long process of seating the 600 guests in St. George’s Chapel was unimpeachably English, the hymns during the service were sturdy standards, and the two anthems sung by the choir, though written four and a half centuries apart, nestled snugly in the same Anglican tradition. But we also knew we were in for some music that were absolutely unprecedented for a royal wedding. A gospel choir singing both Ben E King’s 1960s pop song Stand by Me, and ‘Matriarch of R & B’ Etta James’ version of Civil Rights anthem ‘This Little Light of Mine’, were things no-one could have predicted. Would it all hang together?...