It's widely thought Shostakovich was really thinking about the 1956 Hungarian uprising in this piece - in what is often called a film score without a film. The graphically descriptive music lacks the tight organization of his better-known symphonies, behaving like four tone poems that alternately depict the lonely quiet before an inevitable onslaught, the onslaught itself, and then, in one of the more effective moments, an English horn solo that poetically surveys the scorched earth. With a large orchestra further augmented by much percussion, earth-scorching came in many forms.
Under Bychkov, even the most raucous musical events were meticulously delineated, inflected with great specificity about what the music might mean, but also with a particular ear for strangeness. The composer's characteristic gestures came out twisted, contorted, turned upside down, and played backward.
Such was the freedom Shostakovich could exercise when faking his role of a good Communist and not needing (on this occasion) to be a great symphonist. All sections of the Philadelphia Orchestra played brilliantly and meaningfully, especially English hornist Elizabeth Starr Masoudnia.
Sorry to give the concerto short shrift, especially as pianist Bronfman was reaching beyond the big-fisted repertoire with which he's most associated. His innate technical precision served him well for the filigree lines of Beethoven's most introspective, poetic concerto, seconded by Bychkov's collaborative sense of creating an integrated view of the concerto, even amid the second-movement confrontation between orchestra and soloist.
Bronfman's smooth veneer wasn't entirely a plus here. In terms of penetrating the piece, he seemed to go only halfway, and less than that in the first-movement cadenza. But in a concerto like this, halfway is still a fair distance.
Additional performance: 8 p.m. Saturday at the Kimmel Center. Information: 215-893-1999 or www.philorch.org.