As a composer, Sampo Haapamäki (b. 1979) has established his very own voice, which has attracted considerable interest in Finland and internationally. Central to this are the quarter tones that he has been exploring in his compositional work for more than 15 years. Haapamäki has composed acoustic music for various ensembles from orchestra to choir, as well as electro-acoustic multichannel music. He has also helped to develop new instruments for the performance of quarter-tone music. Haapamäki’s Concerto for Quarter-tone Piano and Chamber Orchestra is a brilliant example of art music, in which innovation and diligent research work blend to become a natural part of the musical language. The work was premiered by the pianist Elisa Järvi and the chamber orchestra Avanti! in November 2017. The keyboard of the quarter-tone piano used in the performance is a joint design by Haapamäki and Järvi. The concerto is a unified, impressive whole in which Haapamäki’s journey of discovery over the years has been crystallised into an exuberant, strangely beautiful musical language, and the quarter tones are played not only by the piano, but also by an entire chamber orchestra. The composer masters the comprehensive concerto form with a confident touch.