Violin, viola, cello and piano: four voices that behave like variables in an equation, each new combination yielding a different sonic solution. The Handel–Halvorsen Passacaglia unfolds as a finely calibrated dialogue between two strings; Andreae's String Trio weaves a close-knit sonority; Schumann's Piano Quartet speaks with heartfelt lyricism; while Tchaikovsky's The Nutcracker and Piazzolla's The Four Seasons bring familiar melodies and tango rhythms, adding colour and heat. CHEN Yu-wen, LIN Hsiao-chun, LIN Hung-lin and CHANG Yen-wei invite you into the permutations of chamber music, to hear the arithmetic between the parts.