While still a graduate student at SUNY Buffalo in the early seventies, Gena started teaching and directed the Electronic Music Studio at Brock University in St. Catharines, Ontario. He also worked as a lecturer and Director of the Electronic Music Studio at the California State University in Fresno. From 1976 to 1983, Peter Gena served as an Assistant Professor in Music Theory & Composition at the Northwestern University, where he co-directed the Computer Music Studio.
Gena spent almost forty years in Chicago, where he produced, directed, and performed in many events, including NEMO '96, New Music America festival in Chicago, and the International Computer Music Conference at Northwestern University in 1978. Peter was a program director of the International Symposium of Electronic Arts '97 and acted as an artistic director for the New European Music Overseas Festival (1995–96). In 1980, Peter Gena co-founded a short-lived radical performing group Chicago Interarts Ministry with Phil Winsor and Kyle Gann.
His composition style incorporates both electronic and computer-generated approaches, as well as minimalist instrumental works. Gena collaborated with geneticists to develop methods of employing DNA sequences as the basis for musical compositions. As a pianist, he often plays music by John Cage, as well as own works.
Gena's pieces for various media have been presented in USA, South America, Europe, Asia, and Australia. Some of the selected venues and events include Festival d'Automne (2004), Berkeley Art Museum (2003), Brisbane Powerhouse, Ars Electronica Center (1999), Festival Aspekte (1997), Akademie der Künste, Berlin, Museu Da Imagem E Do Som in São Paulo, Merkin Hall in New York, and New Music America festivals '81–82 and '90.
He received grants and awards from the National Endowment For The Arts, Meet the Composer, Internationale Ferienkurse für Neue Musik, Darmstadt, The School of the Art Institute of Chicago, Northwestern University, CSU Fresno, and SUNY at Buffalo. Peter Gena was granted a rank of Chevalier Dans l'Ordre des Palmes Académiques by the French government.