Groven's musical style is heavily influenced by his folk music background, both harmonic and formal. The
blue notes common in folk music were often compensated in classical orchestra through imaginative use of overtones and in orchestration. Groven's harmonies reflects often the harmonies of the hardanger fiddle, which is commonly played on two or even three strings at a time. He also extracted harmonies from the Norwegian
cither, the
langeleik, and the
willow flute. It has been pointed out that Groven's harmonic principles are not far from the principles of the early
Flemish Renaissance composers, such as
Dufay and
Jacob Obrecht. Like them, he often uses the sixth-chord, with a third at the bottom. Groven often thinks rather
polyphonically, and this can also be traced to the hardanger fiddle, as well as to his admiration for
Bach. In early years, critics accused him of
atonality, but in fact, Groven's music is quite tonal. He can, however use drastic
modulations, which in this context turn out as fairly logical. Apart from this, he uses the old modes that are present in traditional Norwegian music. One has to remember, though, that he never heard much of the early Flemish music, or even his older contemporary
Stravinsky, and yet similarities can be found. Those similarities can be explained out of tonal feeling and tradition. Stravinsky in the early stage of his production used Russian folk music in an experimental way, like Groven. Groven's form is metamorphic. He often uses a kind of
fortspinnung, and turns themes over to new themes gradually, in a very organic way. Groven did not believe in the concept of
absolute music. He stated rather that "all music is about something". Thus, one will find that most of his works are based on literature, poems or novels, or even plays. He wrote a number of songs over poems written by
Henrik Wergeland, and choral works based on texts by the Norwegian novelist and playwright
Hans E. Kinck (1865–1926) and poet Ingeborg Refling Hagen. His
piano concerto and two symphonies are also based on works by the latter two authors. Groven also composed music for hardanger fiddle, experimenting with new ways of tuning the instrument, and wrote a number of folk tune arrangements for his own organ, using blue scales and irregular intervals, not to be achieved on a regular equal-tempered piano. He wrote also a number of essays on the topics of pure tuning and the overtone scale, as well as an essay of his own invention, the pure-tuning automath. ==Personal life==