Paul Simon showed why he’s a songwriter with few peers at Constitution Hall. (All photos by Josh Sisk/FTWP)

Except it wasn't Paul Simon doing the singing. It was … some dude. (We later found out his name is Paul Fournier, a local 42-year-old patent attorney. For more on that see Reliable Source.) Simon missed his vocal cue on the song (he's 69, give him a break), and then simply invited Fournier up on stage to sing. The Other Paul had all the rock star charisma of the original, which is to say none at all — short brown hair, a tucked-in button-up shirt, dark slacks, goofy grin. Yet he proved to be a complete natural. His rendition wasn't simply passable, it was near perfect.

That the most memorable moment of the concert came with the star attraction happily observing was fitting. Simon's status as an American songwriting superman is set in stone. He's beyond simply receiving honors; new ones are basically invented to praise him. In 2007 he was awarded the Library of Congress's Gershwin Prize for Popular Song, and part of the reason Simon was such a deserving inaugural recipient was on display Wednesday night. He exists to serve his songs, and never the other way around. So if that means letting a patent attorney sing the final song of a set, or stepping aside to make room for an extended washboard solo, so be it. Simon is the creator and the vessel but doesn't need to be the focus. He seemed to get as much joy simply sharing the stage with an eight-piece backing band of astounding musicians — each of whom excelled at multiple instruments — as singing his generation-defining songs.

Not that he didn't share plenty of those from his nearly 50 year career. The first encore was a solo version of Simon & Garfunkel's classic "The Sounds of Silence." (There wasn't much stage banter from Simon, but he did say he remembered "playing here with Artie in the '60s.") "The Only Living Boy In New York," "Still Crazy After All These Years" and "50 Ways to Leave Your Lover" were also clear fan favorites.

Simon sang in his usual low-key conversational cadence, offering lyrics that went from playful exercises in wordplay ("I been workin' at the car wash/I consider it my day job/'Cause it's really not a pay job") to simple and poignant. His still-sweet voice makes a chorus of "Help me, help me/Thank you/For listening to my prayer," sound especially comforting.

Simon also paid tribute to some of his songwriting heroes by covering tunes by Jimmy Cliff (a bouncy "Vietnam"), the Beatles (an elegant "Here Comes the Sun") and trading guitar licks with bandleader Mark Stewart on the rock chestnut, "Mystery Train."

On the surface it seemed bizarre that someone with such an overflowing catalogue would take up precious set list space with other people's songs. But Simon's not one to hog the spotlight. He wasn't even the most scene-stealing Paul on this night.