At the age of 20, Matsumura began his formal studies privately as a pupil of Yasuji Kiyose. He was hampered from attending a university because of a personal illness, but nevertheless went on to study with Ikenouchi and Akira Ifukube. He soon received recognition as an accomplished composer through winning both the first prize at the 1955 NHK Manichi Music Competition and the 24th Concours of Japan (1955) for his orchestral piece Joso to kyosoteki areguro (Introduction and Allegro concertante).
In 1957, Matsumura joined Ikenouchi's Shinshin Kai group. That same year he composed another orchestral work, Achime, which, like much of Matsumura's music, employs updated versions of Impressionist harmonies, rich and dense orchestrations with intriguing timbral combinations, and very effective expressive gestures. This was followed by the Cryptogramme for orchestra (1958), the Music for String Quartet and Pianoforte (1962), his Symphony (1965), the poetic musical drama Bonno no fue (Flute of evil passions/or, The Devil's Passion Flute, 1966) which adds traditional Japanese instruments (the flutes ryuteki and nohkan) to a Western orchestra, and his Prelude for Orchestra (1968) which won the 17th Otaka Prize in the year of its composition. In 1969, he composed further orchestral works which reveal a steadily growing intensiveness of emotion: the Poem No. 1, Apseras, Deux Berceuses à la Grece, Shikyoku (Poem), and Sorei kito (Totem Ritual).
The compositions of the 1970s began with Apseras no niwa (The Court of Apseras, 1971), Poem II for orchestra (1972), Two Poems by the Prince of Karu (1973), and the Piano Concerto No. 1 (1972) which won both the Fukuyama Prize and the Arts Festival Excellence prize in 1973.
Matsumura's Piano Concerto No. 2 (1978), winner of both the 27th Otaka Prize (1978) and the Suntory Prize (1979), employs traditional (although not especially "flashy" or technically difficult) patterns associated with the European piano concerto to make an original and moving statement. As the first movement opens, a dense dramatic trilling underscores a noble brass theme with a solo violin as a tragic commentor, and we are led into a kind of flashback on a mysterious history. There is no specific program but the emotion of the music is irresistible.
In 1978, Matsumura composed the compelling Akatsuki no Janka (Hymn to Aurora) for chorus, and in 1979, the Poème pour Shinobue et Biwa for traditional Japanese instruments, and The Drifting Reed.
The 1980s saw another burst of creative activity with the Fantasy (1980), a Poème pour Alto Saxophone et Biwa (1980) with unusual timbral and gestural combinations, the Air of Prayer (1984), and the expansive Concerto pour Violoncelle et Orchestre (1984), The Patient Waters (A Lyric Tragedy) (1985), Piano Trio (1987), Pneuma for Strings (1987), and the Offrande Orchestrale (1989). His later work includes Chinmoku (1994).