PRINCETON - The quiet timpani rumble that opens Sibelius' Symphony No. 1 always seizes one's ears as the clarinet solo seemingly wanders into Nordic parts unknown.

That passage had a special charge at Princeton Symphony Orchestra's Sunday concert at Richardson Auditorium, like an unsettling precursor to an earthquake. Speaking volumes with such precise, well-molded sound indicated how far this orchestra has come under music director Rossen Milanov.

Playing well is one thing, but the orchestra now has an immediately noticeable collective personality. Strings have lean homogeneity that handily encompassed the range of expression demanded, most significantly, by Sebastian Currier's 1997 Microsymph, whose five movements go to all sorts of engaging symphonic extremes, and came out polished and comprehending.

The weekend was a Milanov doubleheader that included an excellent all-Brahms concert on Saturday at Rutgers University-Camden with his Symphony in C - suggesting that if this kind of artistic evolution was waiting to happen following his 2011 departure from his 11-year associate conductor tenure with the Philadelphia Orchestra, he should have left sooner.

Even with a revolving postgraduate personnel, Symphony in C always offers a more complete account of Milanov's talent than one-rehearsal Philadelphia Orchestra performances. Brahms' Symphony No. 3 on Saturday wasn't just full of smart interpretive decisions, it had eloquent volatility whenever the thematic development went into high gear, plus incredibly expressive phrase readings (the cello theme in the third movement) that made the symphony something of an autobiography.

Soloists for both concerts enjoyed a genuine collaboration with Milanov, allowing a magnitude of expression that felt barely contained by the instruments at hand. In Camden, Alon Goldstein's effortlessly projected sonority assured that the most delicate trills need not be forced in Brahms' Piano Concerto No. 1. In Princeton, Zuill Bailey's bristling but elegant playing in Schumann's Cello Concerto sidestepped the usual hard labor heard in the piece, making its intensity even more powerful for being so distilled.