Nicholas Isherwood has sung in the world's leading festivals (Salzburg, Aix, Festival d'Automne, Avignon, Almeida, Biennale di Venezia, Holland Festival, Munich Biennale, Wien Modern, Händel Festivals in Göttingen and Halle, Tanglewood, Ravinia, etc.) and opera houses (Royal Opera House, Berlin, Frankfurt, Stuttgart, Amsterdam, Lyon, Châtelet, Théatre des Champs Elysées, Rome, Torino, Genova, La Fenice, La Scala, etc.), working with conductors such as Joel Cohen, William Christie, Peter Eötvös, Gabriele Ferro, Nicholas McGegan, Paul McCreesh, Zubin Mehta, Kent Nagano, Helmuth Rilling, David Robertson, Gennadi Rozhdestvensky and Arturo Tamayo.
Isherwood has worked closely with composers such as Sylvano Bussotti, Elliott Carter, George Crumb. Hans Werner Henze, Mauricio Kagel, György Kurtág, Steve Lacy, Olivier Messiaen, Giacinto Scelsi and Iannis Xenakis.
Isherwood collaborated with Karlheinz Stockhausen for 23 years, singing numerous world premieres. He has improvised with Steve Lacy, Joelle Léandre, David Moss and Sainkho Namtchilak. He has made 55 compact discs for labels such as Erato and Harmonia Mundi and has appeared in three films for television.
An active pedagogue, he has taught master classes at schools such as the Paris Conservatoire, Musikhochschule Köln, Salzburg Mozarteum and Conservatorio Giuseppe Verdi and held positions at SUNY Buffalo, Notre Dame, Calarts and the Ecole Normale de Musique. His book Techniques of Singing, will be published by Bärenreiter Verlag next year.