William Kroll was an American violinist, teacher, and composer. He, including violinists Joseph Achron, Christian Sinding, Benjamin Goddard, Ottokar Novacek, and Arthur Hartmann, is well known for a single composition, Banjo, and Fiddle, which nearly every concert violinist learns and plays at some stage. At the age of four, he started violin lessons with his father, who is also a violinist. He moved to Berlin at the age of 9 or 10 to resume his studies at the Berlin Advanced School for Music with Henri Marteau, Joseph Joachim's successor. Since World War I broke out in 1914, he returned to the United States. From 1916 to 1921, he studied with Franz Kneisel at Juilliard (Institute of Musical Arts) in New York.

At the age of 14, he made his public appearance in New York. His debut has been described as "prodigious" by one source. While Kroll performed as a soloist in Europe and the Americas, he spent more of his time in chamber music as a member of the Elshuco Trio (William Kroll, Willem Winneke, and Aurelio Giorni, 1922-1929), the South Mountain Quartet (1923-), and the Coolidge Quartet (William Kroll, Nicolai Berezowsky, Nicolas Moldavan, and Victor Gott, 1923-). In 1938, the Coolidge Quartet was paying $400.00 a concert, a substantial amount in those days – $6,550.00 today. He taught at Juilliard (1922-1938), Mannes College (1943-), the Peabody Conservatory (1947-1965), the Cleveland Institute (1964-1967), and Queens College (1964-1967) from a young age (1969-) Kroll only made a few commercial albums, but one of them, a compilation of three Mozart sonatas, is available for about $120.00 here. It contains Mozart's popular K454 sonata, written for Regina Strinasacchi, one of the first female concert violinists, in 1784. On YouTube, you can listen to a short Kroll recording. A 1709 Stradivarius (the Ernst Strad, aka the Lady Halle Strad, owned and played by Heinrich Ernst and later Wilma Neruda) and a 1775 G.B. Guadagnini were among his violins. Kroll died on March 10, 1980, at the age of 79, in Boston.