William Herman Potstock (Wilhelm Hermann), (1872–1941) was a German American musician and composer. His best known work "Souvenir de Sarasate" combines different techniques (left-hand pizzicato and double stops) and is a popular virtuoso piece of intermediate violin students.
Potstock was born in Northern Germany; he emigrated with his family via Bremen (Germany) to the U.S. in 1881. He lived and worked as a self-employed music teacher and musician in Chicago, where he died. In 1895 he married Martha Bock. They had two children, Stella (born 1896) and Eugene (1901-1979). His daughter was also a musician.