Yesterday at Milwaukees Summerfest, Warren Haynes pulled double duty once again performing with Govt Mule and then the Allman Brothers Band. In both instances he welcomed guest guitarists to the stage. Towards the end of the Mule set Mason appeared on guitar for two of his memorable compositions, Sad And Deep As You and Feelin Alright. A bit later in the evening during the ABB performance, blues guitarist Larry McCray stepped into the fray during a cover of Good Morning Little Schoolgirl.’ The Mule has only more scheduled US date this summer, on August 6 at Jones Beach with Trey Anastasio, while the Allman Brothers Band continues its summer tour tonight in Toledo.