Some of the best moments in the supposedly ritual-steeped world of classical music are when you have no idea where you are or where you're headed. The fact that your ears were unmoored and sent wandering repeatedly by the Beaux Arts Trio at the ultra-venerable age of 52 made Wednesday's concert at the Kimmel Center's Perelman Theater a model of artistic renewal - one that's not nearly as common as it should be.

No single concert I've heard from the Beaux Arts offered so much, and on so many levels. This isn't sentimentality talking - now that the 2007-2008 season has been announced as the ensemble's last. Plenty of other venerable chamber groups tell my ears that retirement is overdue.

The trio routinely reaches out to living composers: At this year's Philadelphia concert, that was Mark-Anthony Turnage, the Brit who made his reputation on bracing pieces that look classical but behave like punk rock. His 2005 piano trio, A Slow Pavane, is said to be influenced by Miles Davis and American blues. The title refers to the often-melancholy Elizabethan dance. The music had a lamenting air and felt more mercurial than a jam session, with tense interplay between piano bass notes and the united front of violin and cello. Melodies were angular and emotionally earnest. It ended with penetrating chords delivered with a coloristic singularity - clean and decisive as polished metal but with an unexpected, chartreuse-y shade.

Shostakovich's Piano Trio No. 2 Op. 67 left you lost in other ways: At the beginning, you're not even sure what the instruments are supposed to be. Thanks to high string harmonics, the sounds suggest a glass harmonica or whistle. As with other Shostakovich works written after his censure by Stalin, the journey is full of disguised meaning. Is the composer screaming at the walls? Employing folk dance to be nasty, funny or tipsy? The catch-all answer is, "Probably but not definitely."

Now in his mid-80s, pianist Menachem Pressler was in thoroughly secure form. As with many senior musicians, his facial expressions suggest he's having unfiltered private moments in public. The musical rewards are priceless. Schubert, represented by his "Notturno" and Piano Trio Op. 99, may be Pressler's core composer since no pianist does distilled simplicity better, and no composer benefits more from it (with the possible exception of Grieg, whose solo piano miniatures were recorded by Pressler decades ago to great effect).

Violinist Daniel Hope and cellist Antonio Meneses haven't always shared the stage with ideal equality. But Hope now contains his many ideas within a more intensely restrained manner. Every repeating sequence was phrased with specificity and individuality. This made Schubert's musical events so eventful as to be explosive - which was completely convincing, but so atypical you had to revise your mental image of the composer.

Contact music critic David Patrick Stearns at dstearns@phillynews. com. Read his recent work at http://go.philly.com/ davidpatrickstearns.