Alma Mahler played piano from childhood and in her memoirs reports that she first attempted composing at age 9. She studied composition with Josef Labor beginning in 1895. She met Alexander von Zemlinsky in early 1900, began composition lessons with him that Autumn and continued as his student until her engagement with Gustav Mahler in December 1901, after which she ceased composing. Up until that time, she had composed/sketched many Lieder and worked on instrumental pieces as well as a segment of an opera.
She resumed composing sporadically after 1910. Only a total of 17 songs by her survive. Fourteen of her songs were published during her lifetime, in three publications dated 1910, 1915, and 1924; it is unclear whether she continued composing at all after her last publication. Three additional songs were discovered in manuscript posthumously; two of them were published in the year 2000, and one remains unpublished.
Her personal papers, including music manuscripts, are held at the University of Pennsylvania, and at the Austrian National Library in Vienna. Her music is still performed and recorded today.