Zemlinsky's grandfather, Anton Semlinski, emigrated from Žilina, Hungary (now in Slovakia) to Austria and married an Austrian woman.

Alexander's entire family converted to the religion of his maternal grandfather, Judaism, and Zemlinsky was born and raised Jewish.

[7] Impressed with Zemlinsky's music, Brahms recommended the younger composer's Clarinet Trio (1896) to the N. Simrock company for publication.

His reputation as a composer was further helped when Gustav Mahler conducted the premiere of his opera Es war einmal (Once Upon a Time) at the Hofoper in 1900.

[15] She reciprocated his feelings initially; however, Alma felt a great deal of pressure from close friends and family to end the relationship.

Following Ida's death in 1929, Zemlinsky married Luise Sachsel in 1930, a woman twenty-nine years his junior, and to whom he had given singing lessons since 1914.

With the rise of the Nazi Party, he fled to Vienna in 1933, where he held no official post, instead concentrating on composing and making the occasional appearance as guest conductor.

[18][19] Their collection, which included "a work by Schiele, various engravings, carpets" was, according to the German Lost Art Foundation, "released and presumably exported to the USA.

Zemlinsky's best-known work is the Lyric Symphony (1923), a seven-movement piece for soprano, baritone and orchestra, set to poems by the Bengali poet Rabindranath Tagore (in German translation), which Zemlinsky compared in a letter to his publisher to Mahler's Das Lied von der Erde.

Other orchestral works include the large-scale fantasy, Die Seejungfrau (The Mermaid), based on the tale of the same name by Hans Christian Andersen.

However, some of his late works such as the Symphonische Gesänge, Sinfonietta and the third and fourth string quartets move away from post-Romanticism towards a leaner, harder-edged idiom that incorporates elements of Neue Sachlichkeit, Neoclassicism, and even jazz.

As a conductor, Zemlinsky was admired by, among others, Kurt Weill and Stravinsky, not only for his notable interpretations of Mozart, but also for his advocacy of Mahler, Schoenberg and much other contemporary music.