Jeffrey Thomas has the touch with Bach's B Minor Mass, a showcase piece combining all the facets of Bach's art into a gigantic musical fresco. It takes tremendous love and concentration to get down to the thousands of nitty-gritty details and work them out so that the performance becomes drama and not just an expertly-played, intimidating mass of sound. Anyone who has heard the American Bach Soloists recording of the piece, with Thomas conducting, knows that the coming concert on Sunday, the crowning event of ABS' Summerfest programs, will rend the heart during the “Crucifixus” and blaze paths of glory in the “Osanna.” You love Bach? You gotta hear this.