In the matter of programming, most major American orchestras on stateside tours adhere to the rule “Do no harm”, with the bland succeeding the bling. Not the San Francisco Symphony under Michael Tilson Thomas. The two menus with which the conductor will travel the US west coast this month add up to a series of encounters, a mosaic of one musician’s predilections, its fragments cunningly juxtaposed to alternately soothe and inflame the passive ear. Tuning out in these circumstances is not an option.

Opening the first programme is the suite that Aaron Copland drew from his score for the 1940 film adaptation of Our Town, an inspired sonic correlative to Thornton Wilder’s portrait of a pre-urban America that probably never existed. If Tilson Thomas lingers a bit too lovingly on the serene open harmonies and snatches of hymn tunes, the spontaneous outpouring of feeling from the podium makes us eavesdroppers on an act of communion.