The son of Jan Kusiewicz, he studied both piano and singing at the Gdańsk Academy of Music, where he started to teach immediately upon finishing his own studies; in later years, he taught also in Bydgoszcz.
Other than that, he made a good career on the concert podium, in both oratorio and lied: not only throughout Poland, but in Berlin, Munich, Cologne, Brussels, London (Royal Festival Hall), New York City (Carnegie Hall), Leipzig (Gewandhaus), Vienna (Musikverein), Stockholm, Milano, Moscow, Montréal, Seoul...
In opera, he sang primarily baroque music (Warsaw, Gdańsk, Krakow, Wrocław, Łódż, Frankfurt, Paris/Théâtre des Champs-Élysées), though his most important operatic role was Edrisi in Król Roger by Karol Szymanowski, which he sang in a series of concert performances conducted by Charles Dutoit (Paris, Montréal, New York, Tokyo). Another specialty of Piotr Kusiewicz was contemporary music by Polish composers (Krzysztof Penderecki, Witold Lutosławski, Krzysztof Baculewski, Edward Pałłasz, Juliusz Łuciuk, Paweł Łukaszewski and Zbigniew Preisner).
Reference: Kusiewicz's now defunct website
I wish to thank Piotr Kusiewicz for the pictures.