It was in this coffeehouse that he met many men of letters including Friedrich Torberg, H. C. Artmann, and occasionally Elias Canetti, as well as Hans Weigel, and Helmut Qualtinger, with whom he later on collaborated and performed.

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.

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).

"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),[6] are now titles that are part of the Austro-pop cannon.

[8] The 3-CD compendium is the first release in the past 20 years, containing new songs, and interpretations of old hits by artists like Brian Eno, Xavier Naidoo, Thomas D, and The Walkabouts.

Heller invented the motto for the Football World Cup, Die Welt zu Gast bei Freunden (A time to make friends).

For the World Cup, Heller planned an opening gala in Berlin's Olympic Stadium, where Brian Eno, and Peter Gabriel would be involved.

In the late 1960s, Heller joined as a financier in the film, Moos auf den Steinen, with Erika Pluhar in one of the main roles, for which he claims to have used up his inheritance.

It was not long before he was in front the camera as an actor: Heller played roles in Hans-Jürgen Syberberg's Hitler: A Film from Germany, in Fear Not, Jacob!

[de] by Radu Gabrea, in Doktor Faustus by Franz Seitz, and in Peter Schamoni's Frühlingssinfonie, in Maximilian Schell's 1979 film, Geschichten aus dem Wienerwald, which is based on Ödön von Horváth's play.

In 1969, Heller participated in a televised version of Arthur Schnitzler's tragicomedy, Das weite Land [de], directed by Peter Beauvais.

Heller lives in an apartment in the Palais Windisch-Graetz [de] in Vienna's Innere Stadt quarter[10] that is owned by the Augustinian monastery of Klosterneuburg.