He performed at the Théâtre de la Monnaie in Brussels several times between 1964 and 1983, including the parts Orest in Elektra by Strauss, Rocco in Beethoven's Fidelio, Marke in Tristan und Isolde and Gurnemanz in Parsifal.
[7] In concert, Nienstedt sang the bass part in Bach's St Matthew Passion at the 1977 Osterfestspiele Salzburg.
Herbert von Karajan conducted the Wiener Singverein and the Berlin Philharmonic, with Peter Schreier as the Evangelist and Jose van Dam as the vox Christi.
He appeared occasionally, for example in 1980 as the narrator in a performance of Honegger's König David by the Rheingauer Kantorei and the Radiosinfonieorchester Frankfurt in the Marktkirche Wiesbaden, with soloists Klesie Kelly and Claudia Eder.
[10] As a teacher, he taught voice at the opera class of the Peter Cornelius Conservatory of Mainz, from 1987 acting at the opera class of the Nordwestdeutsche Musikakademie Detmold (now Hochschule für Musik Detmold), and as professor of voice at the Konservatorium der Stadt Wien (now Konservatorium Wien Privatuniversität).