27 February 1921, Szászváros [Orăştie, Romania] - 6 December 2007, Budapest.

He started to study music in the private music school of Ilona Csipkés, in Kolozsvár. Later on, he visited the local High School of the Reformed Church. In 1939 he moved to Budapest, where he matriculated to the composing department of the Ferenc Liszt Academy of Music and the French-Hungarian department of the Péter Pázmány University (predecessor of the Lóránt Eötvös University) and became a member of the Eötvös Workshop. In 1943 he received the Master of Arts degree and one year later the teacher qualification. At the Academy he studied composing from 1939 to 1946, first with Zoltán Kodály, then with Albert Siklós and later with János Viski. After graduation he won a scholarship to the Accademia di Santa Cecilia and studied there from 1947 to 1948 as pupil of Goffredo Petrassi.

After the war he began to write music reviews to the periodical „Magyarok” (Hungarians) in Debrecen. In 1950 he became teacher at the music history and music theory department of the Music Academy. With Bence Szabolcsi and Dénes Bartha he founded the Hungarian Department for Musicology. Kodály’s catalogue was released in 1953, Bartók’s bibliography in 1955, and one year later he published Bartók’s complete catalogue in chronological order. In 1960 he wrote a book about Arthur Honegger.

From the 60’s he has put more emphasis on his composing activity. In 1964 he wrote Tre pezzi per flauto e pianoforte, which was presented by Severino Gazzelloni in Darmstadt, Madrid and Venice. In 1969 he had international success with his Concerto No. 3., which was a request from Frigyes Sándor and the Ferenc Liszt Chamber Orchestra and also won first prize 1970 in Paris at the international Tribune of radio stations. He composed Concerto No. 4. in 1970 to the request of János Sándor and the Philharmonic Orchestra of Győr.

In 1972 he composed two works for large orchestra: Trasfigurazioni for the 25th Anniversary of the Radio Orchestra and Musica per orchestra, which was a request of the capitol city for the 100th Anniversary of the reunion of Pest, Buda and Óbuda. In 1973 he composed Musica concertante for the Budapest Chamber Orchestra, conducted by András Mihály, while the Preludio, adagio e fuga for the Dresdener Staatskapelle. The Concerto No. 5. („Lehellet” - Breath) was a request from the Hungarian Radio for the 50th birth anniversary of György Lehel.

From 1982 he has written more vocal works, like the choral works In Pharisaeos and Planctus Mariae, and the Fabula Phaedri (comissioned by the King’s Singers), as well as Miserere. Canto d’autunno was a request of the Wales BBC in 1986, while he wrote Paesaggio con Morti (dedicated to Péter Frankl) for the St. Magnus Festival in Orkney Island, Scotland. His String quartet was comissioned by the Dutch Orlando String Quartet. The Elegy was composed 1993 on the occasion of the Biennial in Berlin.

Szőllőssy was an active composer regarding applied music, too. Between 1954 and 1977 he composed music to 31 movies, 17 stage plays and 18 radio plays.

For his outstanding performance as composer and music historian he won many prestigious awards: the Erkel Prize in 1971, the title „Merited Artist” in 1974, the title „Distinguished Artist” in 1982, the Kossuth Prize in 1985, the Bartók-Pásztory Prize in 1986 and 1998. He was also honored with the title Commandeur l'Ordre des l'Arts et des Lettres (1987), the Grand Prize of Cultural Heritage (2002), the Starred Middle Cross of Merit of the Hungarian Republic (2006) and the Széchenyi Prize (2007). In 1993 he became member of the Széchenyi Literature and Art Academy.