Johannes Keller's artistic focus is Early Music as well as contemporary music. As a harpsichordist and ensemble leader, he collaborates with various international venues and artistic formations. He is particularly interested in connecting his musical expertise with other art forms. Keller's activities as a researcher involve microtonal polyphony of the 16th and 17th centuries. He is currently working on his PhD project about Nicola Vicentino's "Arciorgano". Since 2013, he has taught the theory class "Intonation and Temperaments" at the Schola Cantorum Basiliensis.