He was appointed professor at the Hoch Conservatory in Frankfurt in 1890 and also teacher of harmony at Julius Stockhausen's Vocal School.

[1] Humperdinck's reputation rests chiefly on his opera Hänsel und Gretel, on which he began work in Frankfurt in 1890.

Then, using a libretto and thematic suggestions by his sister Adelheid Wette, rather loosely based on the version of the fairy tale by the Grimm Brothers, he composed a singspiel of 16 songs with piano accompaniment and connecting dialogue.

With its highly original synthesis of Wagnerian techniques and traditional German folk songs, Hansel and Gretel was an instant and overwhelming success.

He also collaborated in the theater, providing incidental music for a number of Max Reinhardt's productions in Berlin: for example, Shakespeare's The Merchant of Venice in 1905.

[3] Although recognized as a disciple of Wagner rather than an innovator, Humperdinck was the first composer to use Sprechgesang—a vocal technique halfway between singing and speaking—in his melodrama Königskinder (1897).

[1] In 1914, Humperdinck is thought to have applied for the post of director of the Sydney Conservatorium of Music in Australia, but with the outbreak of World War I, it became unthinkable for a German to hold that position.

[4] Also in 1914, Humperdinck signed the Manifesto of the Ninety-Three, declaring support for German military actions during early World War I.

On 26 September 1921, Humperdinck attended a performance of Carl Maria von Weber's Der Freischütz in Neustrelitz, which was Wolfram's first effort as a stage director.