He studied psychology and philosophy in Berlin, and conducting and organ at the Musikhochschule München with Karl Richter, becoming his assistant.

Jena prepared choir and orchestra for performances by the choreographer John Neumeier at the Hamburgische Staatsoper, including Bach's St Matthew Passion in 1981[3][4] and Mozart's Requiem.

[3] Jena prepared and conducted the NDR Chor for a recording of the complete a cappella works by Johannes Brahms from 1981.

[2] He published books about the musicological and theological background of Bach's Christmas Oratorio, The Art of Fugue and St Matthew Passion.

[7] The Hamburg Senate [de] appointed him an honorary professor in 1986 and awarded him the music prize Johannes Brahms Medal in 1987.