[6] He attended the Warsaw Autumn in 1958, where he was exposed to music by Karlheinz Stockhausen, Luigi Nono, Witold Lutosławski and John Cage.

[1][5] Láng was a member of juries of international competitions, sometimes as president, between 1970 and 1990, including contests for choirs, brass wind chamber music, horn, oboe, trumpet, and composition.

[1][7] In his early mature works, Láng adopted the serial techniques that had become fashionable in the early 1960s, showing the influence of Boulez and Schoenberg, but still managing a clever and effective synthesis of these styles with traditional Hungarian elements derived from Bartók in all areas: melody, harmony, rhythm, and texture—a synthesis perhaps best demonstrated in his Variations and Allegro (1965), which is an arrangement of an earlier symphony.

[7][9] His music from this period is marked by an absorption of the theatre, even in chamber and solo instrumental works, such as Monodia for clarinet, which is intended for stage or concert performance.

[7][5] Other important works from the sixties are the first two Wind Quintets (1963 and 1966), a ballet on Thomas Mann's Mario and the Magician (1962), and a Chamber Cantata to words by Attila József (1962).

[9] Another feature of Láng's style is the use of cyclic form, and his later music tends to consist of sequences of short movements constructed from small motifs, which he called "micro-organisms".