As a poet songwriter, his work spans across a period of more than 15 years selecting diverse topics and writing for a German-speaking audience. He has worked with not only international names such as Ástor Piazzolla, Dino Saluzzi, and Freddie Hubbard, but also with Austrian artists such as Toni Stricker, Wolfgang Ambros, and Helmut Qualtinger. Heller's own poetry has been set to music. He has also sung texts by other authors. For instance, "Catherine", from 1970, was set to one of the first hits of Heller. The text came from the then still largely unknown Reinhard Mey, and the music from the Austro-Canadian Jack Grunsky. With Werner Schneyder, he created Viennese German songs that are translated from Jacques Brel, such as "Franz" (after the Brel title "Jef"). Using intimate memories of traumatic childhood experiences, and insights into his life, as well as his Catholic-Jewish origin, he created songs with the title "Angstlied" ("Verwunschen", 1980). Titles like "Miruna, die Riesin von Göteborg" ("Verwunschen", 1980) are, in turn, influenced by the Vienna School of Fantastic Realism. "Das Lied vom idealen Park" ("Narrenlieder" 1985), or, as a duet with Wolfgang Ambros, he also introduced the Bob Dylan cover, "Für immer jung" ("Stimmenhören", 1983), are now titles that are part of the Austro-pop cannon. In 1983, he appeared on "Stimmenhören" with the song "Erhebet euch Geliebte", a song at the time of the peace movement in the early 1980s. Since the early 1980s, he turned increasingly to large public productions, installations and performances, until 1982, where his concert career came to close. In 1985, the album, "Narrenlieder", was released. Between 1967 and 1985, he published a total of fourteen LPs, twelve of those were gold records, and earned him seven times platinum. In 1991, he wrote, looking back on this period: