He made successful concert tours as a conductor of his own works.
His son Willi Kollo was also a composer of light music and his grandson is the celebrated Wagnerian tenor René Kollo.
Kollo was born in Neidenburg, East Prussia. His best known work, the operetta Wie einst im Mai (1913), was the basis of a 1917 Sigmund Romberg operetta in America entitled Maytime.
Kollo also emerged as a composer of revues and sound films in 1915, was one of the founders of the performer's rights organization GEMA, and had his own music publishing company.
He was a German composer of operettas, Possen mit Gesang ( a form of popular German-language music drama, that developed in the late 18th and early 19th centuries), and Singspiele ( a genre of opera), as well as popular songs.