I'd long known of this group, but I'd never been to one of its concerts before.
It started out as a faculty ensemble at the local medical school, and it still has a lot of doctors and other professionals in its ranks, though the only name I was familiar with was the principal violist, who is also a locally noted solo pianist. I also know the conductor, Stephen Paulson, as he is also the principal bassoon for the San Francisco Symphony (and who looks like a cross between Allen Ginsberg and Santa Claus).
They split their concerts between two venues in San Francisco, both tiny auditoriums with extremely bright acoustics. This concert was at the main hall of the San Francisco Conservatory. The place was absolutely packed. Other community orchestras would be so jealous.
As a volunteer group, Parnassus's technical level of playing is outstanding, just about good enough to be professional. Stylistically, they play as you would expect doctors to: brisk, clear-cut, devoid of excess emotion.
This turns out to be the right attitude to approach Tchaikovsky's First Piano Concerto with (Parker Van Ostrand, a Conservatory student, was soloist): no fat, no longeurs, just a little raw Tchaikovsky. Shostakovich's Fifth Symphony, though, came out a bit oddly, with unnervingly soft climaxes in the slow movements, plus an ending so abrupt nobody knew when to clap.