This season's International Chamber Music Series, like most of the UW World series of which it is part, puts its accent on youth and diversity, showcasing groups formed in the last decade or so playing new repertoire, much of it with inter-cultural links. A solidly classical start last October with the Vienna Piano Trio was followed by the Chiara String Quartet with a program including folk-inspired pieces from Chinese and South American composers as well as Bartok's second quartet. Next March's concert by the Ritz Group combining central European classics with music by Afro-American composers will be followed by the Pavel Haas Quartet, named for the Czech composer murdered at Terezin in 1944 and presenting what must be the Seattle premiere of one of his string quartets along with more familiar works by Dvorak and Beethoven. In April the Corigliano Quartet, playing contemporary works by US composers, will bring the season to an end. It is an enterprising one, though long term subscribers must notice the absence of some frequent visitors in past years, not least the renowned Emerson Quartet. The mid-season concert on 23 January by the Belcea Quartet followed the theme of youth. Like most of the season's participants they have achieved prominence during the last few years, and they are new to Seattle. Based and trained in London, though with an interesting Romanian/English/Polish /French mix of players, they were BBC "Young Musicians of the Year", and still more prestigiously the quartet in residence at London's Wigmore Hall, a celebrated center of fine chamber music. But uniquely for the 2007-8 season this concert was devoted exclusively to the classics, indeed the most classical of the classics - Beethoven's late Quartet in E flat, Op 127, and two quartets by Schubert, the single movement Quartettsatz which began the program, and the great Quartet in G major, D.887 which brought it to an end. All three quartets were composed in the 1820s, the Beethoven being the first of his profound late masterpieces in the form, and the Schubert G major quartet one of the products of the prolific final year of his tragically short life. Though barely older than Schubert at the time of his death, the Belcea players gave us playing and interpretation of the highest imaginable standard throughout this demanding program. They have a remarkable dynamic range, and most noticeably an intense and inward pianissimo that makes the listener strain to hear the softest passages. In an epoch when much string quartet playing is extrovertly projected in large modern halls this is rare and valuable: it draws the audience in and makes them almost active participants in the music-making. It was evident from the very first when the agitated soft opening of the Quartettsatz was played with a quiet intensity that enforced attention; and their impassioned and powerful playing in the heavier and more dramatic parts of the program was the more effective because of the contrast. They are also extraordinarily well balanced, with an absolute equality between all the players. This is an aim of all quartet playing, but seldom so well achieved. The first violin, by the standards of many quartet leaders, is a restrained, even sometimes reticent, player though always deeply musical, and all the other members have equal status and equal prominence. In consequence the harmonic richness of the music is fully conveyed and there is an involving feeling of dialogue between the players, which the audience is drawn into. This was particularly noticeable in slow movements: the lengthy slow variations in the Beethoven quartet were delivered with a wonderful inner glow, and the exchanges between the instruments in the Schubert slow movement were exquisitely tender. The performance of the Schubert G major quartet was, overall, especially notable for its power, and its sympathy for the complex, ambiguous and unpredictable emotional landscape which the composer creates in this work. The concert generated a very high quality of attention from an audience which was of a decent size but still left a good number of empty seats in Meany Hall. On the merits of their playing and of the program they chose, the Belcea Quartet should have had a hall packed to the rafters. As an audience we were also - how to put it tactfully? - notably mature. It would scarcely be an exaggeration to say that any young people in the audience were out-numbered by the four on the stage. Maybe the emphasis in this year's series on young performers and on innovative programs will bring more young people in, but there was little sign of that at this concert. Seattle is the Belcea Quartet's first stop on a US tour that takes them to Wyoming, Utah, several California destinations, and also - on 29 January - to Vancouver B C. String quartet playing at this phenomenally high level is a rare experience and one to treasure. It would be well worth the journey to cross the border and hear them again.