Kirchmeyer initially worked as a freelance music critic for the Rheinische Post in Düsseldorf in 1954/55. In 1955, upon the recommendation of the Cologne University Library Councillor Prof. Dr. Willi Kahl, he was recruited by the Kölner Stadt-Anzeiger, where he remained until 1970.
Concurrently, he held various short-term positions, including Head of Section and Head of Department at GEMA, program curator in the chamber music department of Westdeutscher Rundfunk (WDR) Cologne, Editor-in-Chief of the Instrumentenbau-Zeitschrift, and Production Manager of the Wergo Studio series for New Music. Finally, he was a member of the core staff of the WDR Musical Night Program directed by Herbert Eimert.
In 1960, prevailing over competitors Heinrich Hüschen (University of Cologne) and Kurt Stephenson (University of Bonn), he was appointed Lecturer (Lehrbeauftragter) and Subject Representative for Musicology (Music Theory) at the RWTH Aachen University, succeeding Paul Raabe. Simultaneously, starting in the summer of 1961, he succeeded Prof. Kahl as Lecturer for Musicological Bibliography and Scientific Methodology at the Bibliothekar-Lehrinstitut of North Rhine-Westphalia (later the University of Applied Sciences for Archive and Library Science, and subsequently Faculty 23 of the Cologne University of Applied Sciences). From 1966 he served as a Lecturer, and from 1970 to 1972 as the tenured incumbent (Planstelleninhaber) for Musicology at the Rheinische Musikschule Cologne.
In 1972, selected from over fifty applicants, the City of Düsseldorf and the State of North Rhine-Westphalia appointed Kirchmeyer as successor to Jürg Baur as the (final) Director of the Robert Schumann Conservatory of the state capital Düsseldorf. Following the consolidation of the training centers in Aachen, Düsseldorf, Cologne, and Wuppertal into the Rhineland University of Music (Musikhochschule Rheinland), he became the (sole) Dean of the Robert Schumann Institute Düsseldorf of the State University of Music Rhineland in 1973, which held a semi-autonomous status via a specific state treaty.
In 1987, he became the Founding Rector of the Robert Schumann School of Music and Media Düsseldorf (Robert-Schumann-Hochschule), which had gained administrative autonomy following the North Rhine-Westphalia Art Colleges Act. Finally, from 1988 until his retirement, he served as the elected Rector, confirmed twice by secret ballot unanimously, with no opposing votes and no abstentions.
In 1982, he completed his Habilitation at the University of Düsseldorf, qualifying as a Privatdozent (Private Lecturer) for Musicology and Music-Related Media Studies. From 1974, he was Deputy Head of the Examination Office at the District Government of Düsseldorf (Regierungspräsident) for the field of Church Music. Concurrently, starting in the winter semester of 1994/95, he served as Managing Director of the Institute of Musicology at the Robert Schumann School of Music and Media, which he had founded.
He maintained his teaching activities in Aachen until 1982, and in Cologne until his retirement on July 31, 1995. He concluded his teaching tenure at the Düsseldorf School of Music in the summer semester of 1998, and at the University of Düsseldorf in the summer semester of 2000. Throughout his life, Kirchmeyer was never a member of any political party.