He is known as an early promoter of the stage works by Richard Wagner, namely the Ring cycle, which he presented with the sets and costumes of the world premiere at the Bayreuth Festival, first in Leipzig and then on a European tour.

After engagements as a baritone in Berlin, Cologne, Krakow, Ödenburg, Bratislava and Gdansk, he came to the Vienna Imperial Opera in 1862, where he remained active until 1876.

[3] His direction began with a production of Lohengrin; further operas by Richard Wagner followed as well as performances of Verdi's Aida and Bizet's Carmen.

[5] After acquiring the original stage sets and costumes (by Carl Emil Doepler) of the Bayreuth premiere,[6] Neumann undertook a kind of European tour with complete performances of The Ring of the Nibelung by a travelling ensemble.

[3] In May 1882 a guest performance took place in London,[3] with Julius Laube's [de] ensemble from Hamburg[7] under the direction of the Leipzig Kapellmeister Anton Seidl.