A hint of Lynne's future was seen when George Harrison appeared onstage during the encore at Heartbeat, joining in the all-star jam of "Johnny B. Goode".
But Mr. Mason returned to lead an all-star jam on his song "Feelin' Alright."
The performances will be broken up into duets, ensemble parts and solos and the concert will end with an all-star jam.
There had been plans to close the performance with a greatest hits all-star jam, but this idea was shelved.
He hosted all-star jams at numerous clubs, including Ian Copeland's Backstage Cafe.
In addition to the main stage performances, after-hours all-star jams were held at the Brick Street Cafe and at the Rocky Road Tavern.
The festival concluded on Sunday with another "Hoot for Huntington's" - an all-star jam at the Crystal Theater.
IBMA 2009 after-hours all-star jam.
The main draw was the promise of unusual all-star jams, and that's precisely what attendees got, for better and for worse.