The Cologne double bass player Sebastian Gramss is certainly one of the outstanding instrumentalists, composers and conceptualists of the current European music scene. His instrument: the double bass - despite its wide range of sounds certainly one of the most underestimated musical instruments. The new album BASSMASSE 13 / 45 presents studio and live recordings of his ensemble BASSMASSE 13 (with 13 bassists) as well as excerpts from the already legendary opening concert of the Moers Festival 2014 with almost 50 double bassists. With the release of BASSMASSE 13 / 45, the two-time ECHO prizewinner (double bass - national) takes his diverse activities around his personal instrument to a preliminary climax.