He studied music theory and composition from 1919 to 1924 at the Cologne Musikhochschule with Hermann Abendroth, Franz Bölsche [de], and August von Othegraven.
[1] In 1924, he began studies in musicology at the University of Cologne with Ernst Bücken, Willi Kahl, and Georg Kinsky, and read philosophy with Max Scheler (a pupil of Husserl) and Nicolai Hartmann.
From 1927 until 1933 he was employed at the Cologne Radio and wrote for music magazines such as Melos [de] and the Neue Zeitschrift für Musik.
This became the most influential studio in the world during the 1950s and 1960s, with composers such as Michael von Biel, Konrad Boehmer, Herbert Brün, Jean-Claude Éloy, Péter Eötvös, Franco Evangelisti, Luc Ferrari, Johannes Fritsch, Rolf Gehlhaar, Karel Goeyvaerts, Hermann Heiss, York Höller, Maki Ishii, David C. Johnson, Mauricio Kagel, Gottfried Michael Koenig, Petr Kotik, Włodzimierz Kotoński, Ernst Krenek, Ladislav Kupkovič, György Ligeti, Mesías Maiguashca, Bo Nilsson, Henri Pousseur, Roger Smalley, Karlheinz Stockhausen (who succeeded Eimert as director), Dimitri Terzakis, Iannis Xenakis, and Bernd Alois Zimmermann working there.
"[5] In 1950, he published the Lehrbuch zur Zwölftonmusik, which became one of the best-known introductory texts on Schoenbergian twelve-tone technique, and was translated into Italian, Spanish, and Hungarian.