Like a growing number of younger classical players, pianist Christopher O'Riley comfortably straddles the fence between his metier and the pop realm. Trained at a conservatory, he has the requisite concertos and sonatas in his repertoire--namely works by late Romantics (Busoni, Tchaikovsky), modern Russians (Scriabin, Stravinsky, Prokofiev), and Americans (Gershwin). At Ravinia, where I first heard him live, he's been relegated to reviving warhorses (Tchaikovsky's First, Gershwin's concerto) and stoking the tango craze (duo piano arrangements of Piazzolla's tunes). It's not easy to gauge a pianist's musicianship solely on these performances--Beethoven, Mozart, and Schubert are often better tests--but in each instance, O'Riley demonstrated exceptional technique and flair. He also has the gift of putting an audience at ease with his friendly smile, casual dress, and engaging commentary--which has also made him a likable host of NPR's From the Top. This is O'Riley's fourth consecutive year appearing at Ravinia, and he'll have the chance to reveal two additional facets of his musical personality. First, he partners with the esteemed Tokyo String Quartet in a chamber mainstay, Schumann's Piano Quintet in E-flat Major; then he'll play a solo recital of his own transcriptions of music by his favorite rock band, Radiohead. The Radiohead selections, which are packaged in a Sony CD called True Love Waits, are a laudable attempt at casting the band's regret and yearning in a Chopin-esque vein. But they don't quite get to the heart of the songs, partly because they're unable to capture the emotion that Thom Yorke's lyrics convey and partly because O'Riley's transcriptions, while polished and at times virtuosic, recall Keith Jarrett more than anyone in their overreliance on mellow melodic riffs. Still, this noble effort points to new possibilities in the blending of classical and pop. Besides the Schumann, the Tokyo program also includes Haydn's String Quartet in F Minor and In Memory (String Quartet no. 2) by Joan Tower. The Tokyo Quartet, incidentally, has a new first violinist; it remains only half Japanese. Monday, June 16, 8 PM, Martin Theatre, Ravinia Festival, Green Bay and Lake Cook Rds., Highland Park; 847-266-5100.