San Francisco Symphony, Usher Hall, Edinburgh

Unlike other American orchestras on tour, the San Francisco Symphony suffers from a split personality. On home ground it has created an international reputation with a specifically Californian identity, championing the musical idioms and questing minds that have flourished there.

Away from home it wants to swim with the crowd, acknowledging its American-ness with a couple of home-grown bonbons but ashamed to do it properly. This split has occurred only since Michael Tilson Thomas became music director in 1995. His two Edinburgh programmes contained barely 10 minutes of American music.

At the Proms this weekend there will be just one brief curtain-opener, an Ives symphony. Why doesn’t Tilson Thomas have the courage of his convictions?

Judging by the first Edinburgh concert, he has turned the San Francisco Symphony into a well-toned and tuned orchestra, rhythmically smart, but with a personality smothered by its conductor’s ego. Its Edinburgh performance of Tchaikovsky’s First Symphony was neat to a fault – the moody slow-movement theme elaborated with penny-plain phrasing, the third movement charmlessly articulated, the finale almost devoid of accents.

Tilson Thomas did make a point of showcasing the orchestra’s brass in Copland’s Fanfare for the Common Man and the strings, lean and a bit mean, in Ruth Crawford Seeger’s Andante for Strings. That led, without a break, to John Adams’s Short Ride in a Fast Machine: the title said it all.

And yet the concert did yield two outstanding performances. Yefim Bronfman contributed the solo highlight of this year’s festival with a Prokofiev Third Piano Concerto that made musical virtues of speed and dexterity, saying something lucid and delicate where most pianists are merely dazzling, brash and percussive.

No less bracing was Tilson Thomas’s choice of encore – Bernstein’s Candide overture. The San Franciscans let go their inhibitions, playing like a crack Broadway band and sending us out into the chill Edinburgh air humming the tunes.

At the Proms tomorrow and Sunday. Tel +44 020 7589 8212