By Mark Stryker

... Saturday's concert had its heroes. Cellist Andres Diaz, and pianist Jeremy Denk brought to Shostakovich's brooding Cello Sonata a controlled fury and expressive maturity that cast a mesmerizing spell. This is serious and somber music, but Diaz and Denk were alert to the snatches of wit and the omnipresent strains of stark poetry that make Shostakovich's nightmares bearable ...

Denk solidified his position as the most valuable addition to the festival in years with Saturday's fresh reinvention of Mozart's Piano Concerto No. 13, K 415 (in its String Quintet version). More impressive than his note-perfect dexterity and control of color is Denk's ability to rethink this well-known music from scratch. He seems to have reconsidered every harmonic shift, melodic quirk and rhythmic turn. Yet the results breathed with spontaneity.  The brisk scales and arpeggios in the opening allegro came alive with a propulsive flair and visceral emotion. The andante projected heartfelt lyricism and the finale was full of fairy dust, with Denk especially alert to the give-and-take with the ensemble. The young Ariel Quartet (with bassist Craig Rifel) seemed carried along by Denk's charisma.