The Hungarian tenor, László Csabay, had worked first as commercial employee, before starting to study singing at the Franz Liszt Academy in Budapest with Szamosi. He continued his studies with Fritz Feinhals in Munich and Edoardo Garbin in Milan.
László Csabay made his debut in 1932. His first engagements were on the German music stage, with Wanderoper (touring opera), with which he appeared in 1932-1933 in Germany, Belgium and Estonia. In 1933-1935 he sang at the Deutschen Theater Brünn (Brno), and in 1935-1938 at the Volksoper Budapest. In 1937-1938 he participated in the tour of the Salzburg Opera Guild to the USA and Canada. In November 1937 he participated in New York in the American premiere of J. Ibert's Angélique. From 1938 to 1942 he was engaged at the Stadttheater der Schweizer Bundeshauptstadt Bern, and from 1942 to 1946 at the Opernhaus Zürich. In this opera house he sang Buffo and character roles, as: Jacquino in Fidelio, Lorenzo in Fra Diavolo by Auber, Pedrillo in Die Entführung aus dem Serail, Basilio in Le nozze di Figaro, Schuiskij in Boris Godunov, Valzacchi in Rosenkavalier, the four character roles in Hoffmanns Erzählungen, Goro in Madame Butterfly, Wenzel in Verkauften Braut, David in Meistersingern, in addition to numerous operetta roles. In addition he sang in Zürich roles as Tamino in Die Zauberflöte, the Duke in Rigoletto and Cassio in Verdi's Othello. He appeared as a guest at the Grand Théâtre Geneva as Ferrando in Così fan tutte. A high point of his repertoire was also Mime in Der Ring des Nibelungen. In 1942 he participated in Zürich in the premiere of Paul Burkhard's opera Casanova in der Schweiz.
In 1946 László Csabay was invited to join the roster of the Metropolitan Opera in New York, where he appeared until 1951 in 42 roles (first role: Don Curzio in Le nozze di Figaro), including Borsa in Rigoletto, Dr. Cajus in Falstaff by Verdi, Gaston in La Traviata, Ruiz in Troubadour, Monostatos in Die Zauberflöte, Balthasar Zorn in Die Meistersinger von Nürnberg, Laërte in Mignon by A. Thomas and Remendado in Carmen. He also made guest appearances in Pittsburgh (1947), New Orleans, Chicago and San Francisco (1947-1949).
In addition, László Csabay had an important career as concert and oratorio singer. In 1952 he participated in the American premiere of the oratorio Golgotha by Franc Martin. In the USA he appeared under the name Leslie Chabay, while in Europe he appeared under his real name László Csabay. After retiring from the stage, he lived in Sarasota (Florida).
Recordings: RCA (Rodrigo in Verdi's Othello under Arturo Toscanini, Roméo et Juliette by Berlioz), Concert Hall, Victor (Johannes-Passion (BWV 245) by J.S. Bach), Turnabout (Israel in Egypt by George Frideric Handel), Bach Guild (Hungarian Folk Songs, Songs by Béla Bartók and Zoltán Kodály), Concert Hall Society (Der Winterreise by Schubert with the pianist Benjamin Oren); Handel Society/Concert Hall Societ (Alexander's Feast by G.F. Handel with Handel Society Orchestra and Cornell University Chorus conducted by Robert Hull, soprano Leona Scheunemann and bass Keith Falkner, 1952).