[2] In 1910 a highly publicized incident occurred between Weiss and conductor Gustav Mahler during a rehearsal with the New York Philharmonic at Carnegie Hall.
[5] Sources agree that Weiss left the rehearsal and that the orchestra was forced to find another player at the last minute for their impending concert.
After graduating from the Vienna Conservatory he joined the faculty of Theodor Kullak's music school, the Neue Akademie der Tonkunst.
[1] He gave a series of recitals in New York City at Mendelssohn Hall in 1898–1899 where he drew particular praise from critics for his playing of the works of Brahms.
[9] He returned periodically to New York, most notably serving as accompanist to Emma Nevada for performances at the Metropolitan Opera.
He gained a reputation as a great interpreter of the works of Johannes Brahms, Frédéric Chopin, and Liszt.
[3] In 1910 Weiss had a high-profile outburst in a rehearsal with Gustav Mahler and the New York Philharmonic at Carnegie Hall.
[5] Accounts vary, with some sources claiming the men merely shouted and exchanged rude words with one another which ended with Weiss slamming the piano shut and leaving the rehearsal.
[4] Regardless, Weiss's decision to leave the rehearsal required that the orchestra find a last minute soloist for their impending concert,[5] and this event negatively impacted his reputation.
[3] In spite of this incident, Mahler considered Weiss to be the "greatest pianist he had ever heard" and the two men maintained a friendship.
He had a nomadic existence over the next few years, spending time first in Italy and then in Switzerland before returning to Hungary in 1939 where he settled in Budapest.