The Norwegian composer, musicologist, and folk musician Eivind Groven (1901-1977) is increasingly recognised as an important contributor to the music scene from the 1920's onwards. His work on the just intonation problematics has inspired further studies of composition and acoustics, with practical benefits for jazz, folk, and classical musicians. Groven's efforts in the transmission and transcription of folk music have evoked renewed interest among generations of young performers. As a collector, musician, radio broadcaster, acoustician, musicologist, and composer, he has entered the ranks of pioneers in Norway. Path-breaking is arduous, but due to the steadfastness of his vision and humility towards the legacy he inherited, he succeeded in many areas and attracted the respect of renowned people such as Albert Schweitzer, Alois Hába and Arne Nordheim. The book consists of eleven articles, discussing Groven's life and work as composer, ethnomusicologist and researcher, in addition to lists of Groven's works and a bibliography that provides an overview of his contributions to the field of music.