As the Tokyo String Quartet played Monday night at Portland State University's Lincoln Hall, you had to wonder: Was it the players' awareness that this was one of their final concerts that made for such an intense experience, or wasit heightened attention on the part of a listener who knew this was likely a final live encounter with one of the great quartets of our time?

Probably a bit of both, but in any case, it was a memorable night, not just an exemplary concert but a little-- and a little bittersweet -- bit of performance history.

Among the most distinguished chamber ensembles of the last half-century, the quartet formed in 1969 at The Juilliard School, its members previously having studied together at Tokyo's Toho School of Music. When founding violist Kazuhide Isomura and longtime violinist Kikuei Ikeda announced their retirement in 2011, violinist Martin Beaver and cellist Clive Greensmith had originally planned to replace them, but in April they conceded the insurmountable difficulty of rebuilding the ensemble without its two longest-serving players, and a year ago the quartet announced that 2012-2013 would be its last season.

They leave in a blaze of glory. With a legendary set of Stradivarius instruments formerly owned by Niccolo Paganini -- including the viola for which Hector Berlioz wrote "Harold in Italy" -- they played with radiant clarity and smoldering warmth, an undercurrent of lyrical expressiveness uniting an otherwise disparate seeming program of Mozart (the D Major"Hoffmeister"), Zoltan Kodály and Brahms.

Their keen chemistry was a delight to behold. Beaver and Ikeda presented strikingly similar personalities; with a sober, contained demeanor, they left the drama to the action of their bows, turning the minutiae of speed, tilt and distance from the bridge into richly varied tone and long, shapely phrases. Alongside them, their partners offered a study in contrasts: with snow-white hair and neat mustache, Isomura looked like the perfect image of a Meiji-era gentleman and quietly projected leadership from within, while Greensmith bounced in his chair, his body and facial expression as elastic as his sound.

Jon Kimura Parker joined the quartet in the second half for Brahms' F Minor Piano Quintet, a large-scale work that combines intense intimacy with symphonic heft. Parker is an extraordinary chamber musician with uncanny touch and dynamic control, and he matched the nuances of the strings throughout.

Tuesday night's performance was sold out long ago, but you still have one final chance to catch the Tokyo today as they give a master class at 11 a.m. in Room 75 of Lincoln Hall. Parker returns for a solo recital Wednesday, April 10; see focm.org for details.

Before the concert, Friends of Chamber Music executive director Pat Zagelow announced that the organization had been recognized by Chamber Music America with its 2013 award for presenters. Based on FOCM's work this spring alone, including the Jerusalem Quartet's fantastic Shostakovich cycle and now the
farewell performances of the Tokyo, the award is well-deserved.