Ken Johansen was born in Denmark, and grew up in Dallas, Texas. His studies took him first to San Francisco, where he studied with Alain Naudé, a pupil of Dinu Lipatti and Nadia Boulanger; then to Paris, where he studied piano with Gaby Casadesus, and musicianship (harmony, counterpoint, solfège, and score reading) with Narcis Bonet, also a former student of Boulanger and her successor as director of the Conservatoire Americain at Fontainebleau. He holds a Masters degree from the Peabody Conservatory, and a DMA from the University of North Texas, both in piano performance. He has been teaching keyboard skills for piano majors at Peabody since 2002.

Ken Johansen is the author of Harmony at the Piano (Routledge, 2023), a keyboard harmony textbook that helps pianists to learn repertoire more musically and effectively, and has published articles on various topics relating to piano music and pedagogy in American Music Teacher, Clavier, Journal of the American Liszt Society, Piano and Keyboard, and La Revue de Musicologie. He is the creator of From the Ground Up, an extensive series of study editions of various piano works, published on the website practisingthepiano.com. He is one of the co-inventors of Read Ahead, a piano sight-reading app that was developed with funding from the Maryland Innovation Initiative.