Although he was a successful opera singer, portraying the title roles of Britten's Albert Herring and Pfitzner's Palestrina at the Staatsoper Hannover, he is chiefly remembered for his work as an oratorio soloist, especially the Evangelist in Bach's Passions.

[2] Born in Eschweiler, Altmeyer began his performance career while still a voice student at the Hochschule für Musik Köln, where he studied under Clemens Glettenberg from 1953 to 1956.

Then starting in the 1960-1961 season, he was the principal lyric tenor at the Staatsoper Hannover, making his debut there as Tamino in Mozart's Die Zauberflöte.

As an oratorio singer, he performed with major orchestras and musical ensembles throughout Germany, France, Austria, Italy, England, Belgium, the Netherlands and Switzerland.

He also participated in two large and highly successful concert tours of North America and performed at major music festivals such as Bachwoche Ansbach, Lucerne, Montreux, Vienna, Florence, Naples and Venice.