Eder studied until 1948 at the Linz Conservatory, later studying with Johann Nepomuk David in Stuttgart and Carl Orff in Munich. Returning to Linz, he became a teacher at the Linz Conservatory, accepting a position as full professor in 1962. He also conducted the Singakademie in Linz from 1953-60 and founded an electronic music studio in the city in 1959. He became professor of composition at the Salzburg Mozarteum in 1967.
Eder composed in a wide variety of traditional genres, and also wrote scores for film, television, and radio.
Eder's works are mainly published by Doblinger.
- Oedipus (1958/59), H. Weinstock, after Sophocles, 1960 Linz
- Der Kardinal (1961/62), E. Brauner, 1965 Linz
- Die weiße Frau (1966), K. Kleinschmidt
- Konfigurationen 3 (1969), R. Bayr Vienna
- Der Aufstand (1976), Gertrud Fussenegger, Linz
- Georges Dandin (1979), Linz
- Mozart in New York (1989/90), Herbert Rosendorfer, 1991 Salzburg
Note: this list is incomplete
- Concerto Semiserio (2 pianos, orchestra, 1962)
- Concertino for Viola, Winds and Percussion, Op.124 (2002)
- Concerto "Der reisende Schatten" for Viola and Orchestra, Op.116 (1999)
- Concertino for Orchestra (1986)
- Violin Concerto
- Oboe Concerto
- Bassoon Concerto
- Organ Concerto on L'homme armé
- Metamorphosen on a fragment of Mozart (1970)
- ...Missa est (1986)
- Jeu parti for Viola and Piano, Op.102 (1993)
- 3 Sätze (3 Movements) for Viola, Double Bass and Piano, Op.73 No.3 (1983)
- Sonatine for Viola and Piano, Op.34 No.2 (1963)
- String Quartet No. 3 (1986)
- Symphonies, ballets, other chamber works, organ works, choral music, songs
- Don Randel, The Harvard Biographical Dictionary of Music. Harvard, 1996, pp. 239-240.