More than 40 years ago, violist Kazuhide Isomura got together with three other Japanese students at the Juilliard School of Music in Manhattan and formed the Tokyo String Quartet. After touring the globe for upward of 4,000 performances, more than 40 for Music Toronto, with 40 albums and nearly 40 years of teaching at Yale, last night, Mr Isomura played his final Music Toronto concert. This year, after a “Farewell” world tour, the quartet will disband.

The program they played was like a valedictory.Two Bartók string quartets demonstrated the Tokyos’ supreme command of the most impressive string quartet cycle since Beethoven. Bartók’s sixth and final quartet is steeped, appropriately, in the sadness of leave-taking. But we were reassured by the formal elegance, exquisite lyricism and vigorous tempos of their G major Haydn quartet that all will continue to be well with this world.

Kazuhide Isomura’s viola and Clive Greensmith’s cello introduce the motif that defines the first section of Bartók’s String Quartet no. 3 (1927). The music is dissonant to the point of harshness, and daunting to follow because as Bartók said, “I do not like to repeat a musical idea without change”. But the flow of mood is palpable, pulsing and pausing in alarm, the viola’s sad voice mingled with weird tutti twitterings, punctuated by the cello’s angry bow-slapping (col legno). The four movements played as one display Magyar folk elements, the complexities of early Baroque canon and fugato forms, and rustling night-music effects, all held together for fifteen minutes in a unique canvas of nuanced musical colours by the matchless craftsmanship of the Tokyo String Quartet.

It is difficult to picture exactly what world the Bartók conjured, but the first measures of Haydn’s Quartet in G major, Op. 77 no. 1 march us into a courtly world where everything runs, vigorously and assured, like clockwork, and the clockmaker, Papa Haydn, grins good-humouredly down on the pastimes of his cloisonne creatures. As always with Haydn, there is an Adagio touched by sadness, in this case introduced by a chord the Tokyos blend perfectly into a single tone and allow to unwind into four separate strands as naturally as a zephyr-blown lock of hair. In the Menuetto, Martin Beaver’s first violin capers from the foot to the peak of its range, and Haydn’s writing in the frenzied folk-dance Finale allows every player to show just how fine they can be.

It is fitting to the occasion that Bartók’s sixth and final quartet be marked “Mesto” (“Sad”) throughout its four unbroken movements, and that it be introduced by the unaccompanied viola of Kazuhide Isomura. Mr Isomura follows the highly chromatic, doleful melody from forte to pianissimo, exhibiting over a couple of asymmetrical octaves, a lifetime’s mastery of vibrato and bow-pressure. The first movement is folky, vigorous to the point of harsh. In the second and third movements, the initial sadness enunciated by Kikue Ikeda’s solo violin escalates to the ensemble’s bitter, sardonic mockery, aimed at the Nazi takeover of Europe, led by the cello screaming in its highest register above brutal strumming from the viola, and the violins playing deliberately out of tune.

The fourth movement is purely mournful all the way through in homage to Bartók’s mother, who was dying as he was was writing. Complications begin to resolve, a mood of sorrow and acceptance emerges, the musical tone grows lovelier, the viola gives a parting glance at the initial Mesto theme, and the quartet vanishes like a puff of smoke.

Needless to say, there were many standing ovations, and no encore.