Sommerro was born in Surnadal in the west of Norway, and won his way into the hearts of many with his song Vårsøg ('Longing for Spring') in 1977. In the course of his life - as both a performer and as a composer - he has become one of the most experienced voices in Norway, and an institution in the music life of the nation.

His compositions range from simple songs to chamber music, choral music, works for orchestra, music for film and stage, and three operas.

Sommerro has toured many countries in Europe and the US. He was the artistic director for the opening cermony of the Paralympic Winter Games at Lillehammer in 1994. He has received numerous prizes including the prestigious Spelmann Award several times. In 2013 he received the Order of St.Olaf 'in recognition of services to his country and people'. In recent years he has toured extensively and received composition commissions from the US, France, Russia, Slovakia, Sweden and Denmark.

Beside his work as a composer and performer he is a professor in composition, organ-improvisation and couterpoint at Department of Music of the Norwegian university of Science and Technology NTNU in Trondheim.