He was born at Stockerau, Lower Austria, and was taught by his father until 1888, when he became a student at the Vienna Conservatory. He remained there as a pupil of Franz Krenn until 1891. Previously he had composed a grand mass in B flat; an offertory, and miscellaneous pieces. Frotzler was organist at Stockerau and chamber-virtuoso on the piano to Prince Heinrich Reuss IV., and from 1893 until 1897 chapelmaster to Count Nicolaus Esterhazy at Totis, Hungary. Since then he has held the post of chapelmaster at the City Theatre, Linz-on-Danube. Beside the works mentioned Frotzler has composed three operas, Arnelda, produced at Totis in 1894 and which later won the prize of the German-American Opera Society at Philadelphia; Die Liebesring, and Mathias Corvinus, produced at the Pesth Royal Opera in 1896. He also composed three masses; offertories; a symphony; scherzo; valse, and other pieces.