In 1924, Kurtz debuted in Rome, and the following year made his debut in Berlin. He then also played in a piano trio formation, the Spivakovsky Trio, with violinist
Tossy Spivakovsky and his brother
Jascha as the pianist, touring internationally. His first American appearance as soloist Other recordings include the
Cello Sonata of
Sergei Rachmaninoff with
William Kapell, which received praise by
Tim Page of
The Washington Post, and Prokofiev's
Cello Sonata with
Artur Balsam, which was the first recording of the work. Kurtz often played a
Stradivari cello from 1724, named the "Hausmann", after
Robert Hausmann, the cellist of
Joseph Joachim's string quartet. He played several premieres of compositions dedicated to him, including
Ernst Krenek's Suite for cello solo, Op. 84,
Alberto Ginastera's
Pampeana No. 2, and
Darius Milhaud's
Élégie, Op. 251, and Cello Concerto No. 2, which he performed with the
New York Philharmonic conducted by
Artur Rodziński in November 1946. He was the soloist in the first American performance of Khatchaturian's
Cello Concerto, with
Serge Koussevitzky conducting the
Boston Symphony Orchestra in 1948. In later years, Kurtz began prolifically producing new editions of cello repertoire. Widely considered the most important of these editions is that of Bach's six
Suites for cello solo, which he based on
facsimiles of the manuscripts by
Anna Magdalena Bach; Bach's originals did not survive. The edition, which features her manuscripts opposite each printed page, has been considered Kurtz's "most important contribution to the development of the art of the cello". Mary Campbell wrote in her obituary for
The Independent that it is "recognised as the most important edition of the greatest music ever written for the instrument". ==Family==