Born in Hanover, Johannes Hehrmann won several national prizes at the Jugend Musiziert competition (1st prize recorder solo 1991, 2nd prize piano trio 1993). He had lessons with Prof. Hedwig Pahl (violin), as well as with Joseph Polster and during his studies with Prof. Kees Boeke (recorder). He studied violin in Trossingen, Cincinnati and Stuttgart with Winfried Rademacher, Kurt Sassmannshaus, Federico Agostini, Eckhard Fischer, Henry Meyer, as well as the "Tokyo String Quartet" and the Melos Quartet. He has received important impetus in master classes with Dorothy DeLay, Peter Oundjian, Joseph Silverstein and the Artemis Quartet. From 2002-2006 he held a teaching position at the Musikhochschule Trossingen and from 2006 to 2008 he was a member of the Verdi Quartet. After several years of freelance work, he has been a member of the WCO Heilbronn since 2004.

His repertoire as a chamber musician spans various genres and ranges from works of the early Middle Ages to experimental electronic music, in addition to a broad quartet and piano trio repertoire. From 2007-2008, he worked intensively on chamber music works by Olivier Messiaen as part of a scholarship from the Haake Foundation. In 2008, he developed and created a programme for the "Turkish Culture Days" with the multi-award-winning ensemble "Sarband". For several years he has worked on projects with the Stuttgart duo "Spiedkiks". This cooperation resulted in the album "Take Off Your Make Up", which was released on the internet in May 2013 and has since been downloaded over 40,000 times.