This was a bifurcated concert. Michael Tilson Thomas, still recuperating from major surgery a few months ago, decided that a second full program in two weeks was more taxing than his energy level could handle.
So Ludovic Morlot - former music director in Seattle* - came in as a late substitute for the first half. Probably because there was a limit on how much new material he could learn at short notice, the originally programmed William Grant Still piece was replaced with Ravel's Ma Mere l'Oye Suite. This received a soft and gentle performance, ideal for this delicate flower of a work.
Morlot did keep the premiere of the concerto that SFS principal trombone Timothy Higgins wrote for himself. This had been commissioned by SFS and had already been postponed once due to the pandemic. In Higgins' hands, it turns out, the trombone is a rather quiet instrument, even quieter with the mute on, and it tended to get overshadowed by the exceedingly colorful orchestration. An enjoyable piece, with spiky modernism but consonant, and coherent and substantive, not spinning its gears.
After intermission, MTT led an excellent performance of Copland's Appalachian Spring, the full-orchestra version of the complete work. This was especially notable for the sinew expressed in the slower passages, but it was just great throughout. But that's just what we were expecting.
*And the former assistant in Boston who conducted that orchestra when they came for a visit here in 2011, after the resignation of J---s L----e.