Holecek made guest appearances at opera houses in Paris, Barcelona, Rome, Stockholm, Stuttgart, Zürich, Munich, Hamburg, Berlin, and also at the Bregenz Festival.
In Die Fledermaus by Johann Strauss, he played the roles of Falke, Frank and Frosch.
[4] In addition, he participated in a large number of sound recordings as well as television productions and had numerous TV shows of his own.
Together with Heinz Zednik and the Philharmonia-Schrammeln as well as with the Wiener Schrammel Ensemble he made several CD recordings.
Tours with Viennese songs took him to Los Angeles, Montreal, Moscow, and Japan.