"Harvested by Bartók, Kodály and a few others from 1904–5 on, [the authentic folk music of the Hungarian peasant], with its characteristic melodic contours, provided the leaven for a generation of Hungarian composers to create an entirely new musical ethos. There were other influences upon Bartók, among them those of Debussy, Stravinsky and Schoenberg; he also investigated and allowed his music to be colored by folk music other than Hungarian, especially Romanian, Slovakian and Arabic. But it was from Hungarian music itself that he drew the strongest sustenance, Hungarian peasant music that had for generations rubbed shoulders with, influencing and being influenced by, the music of neighboring peoples. “Race purity” in music, he believed resulted in musical poverty: the richest hoard of folk music is fructified by the music it comes into contact with...

Notable in the quartets from No. 2 on is an unprecedented interest in extending stringed-instrument techniques. Before Bartók composers had been content to write mainly within the traditional virtuoso limits, and even Paul Hindemith, a string player himself, had little interest in going beyond the normal or conventional bowing and fingering procedures. These did not satisfy Bartók, who demanded unusual multiple stops, unorthodox fingerings, several different types of pizzicato and glissando and a whole arsenal of special effects that have revolutionized the string player’s approach to his instrument – all despite Bartók’s never having played any but keyboard instruments.

But the importance of his achievement lies not in the ingenuity of the writing or the novelty of the style but in the strength and persuasion of the works that resulted. In all these quartets musical logic prevails; the materials are distinctive and memorable, their manipulation magisterial, and the combination produces an unparalleled series of masterpieces, each with its individual delights – and its individual problems for players and listeners alike."

— excerpt from the original liner notes from ARL3–2412 by Halsey Stevens