Yori-Aki Matsudaira is one of Japan’s most important postwar composers, but his true worth is still not yet fully known. In particular, the multifaceted aspects of his systematic thinking only become apparent when we take a cross-work view of a number of pieces. Accordingly, and in consideration of the need for a retrospective of the chamber music works that particularly reveal his artistry as a composer, organizers initially planned to hold the concert on February 27, 2021. However, due to the spread of coronavirus it was postponed until February 18, 2022, when it went ahead without incident. The concert featured select works representing different eras: “Variations for violin, violoncello, piano” from the fifties (1957); “Coherency for Ensemble ARK” from the seventies (1976); “Genesis” from the eighties (1981); “Sparkle” from the nineties (1997); “Contraposition” from the noughties (2004); and “Game of Poisson for SQ” from the twenty-tens (2011). The concert also featured the belated world premiere performance of Trigonometry” (2014). The event was a valuable opportunity to introduce works composed by Yori-Aki Matsudaira at each turning point of his life together with their correlation to the historical background in terms of music. Organizers consider one of the achievements of the concert to be the facilitation of a high sound-quality archive through a stream of the concert as well as a two-part broadcast on NHK-FM (May and December).