Raden Machjar Angga Koesoemadinata (often written as Kusumadinata, Kusumahdinata, Kusumah Dinata, Anggakusumadinata; known as Pak Machjar or Pak Mahyar ; b. Sumedang, 7 December 1902, d. Bandung, 9 April 1979) is a Sundanese music composer and an Indonesian Musicologist, specializing in pelog and salendro. He invented the Sundanese solfage system da mi na ti la and the Sundanese 17-tone model.
Among the Sundanese people, Pak Machjar is widely known as a Sundanese composer. He wrote Sundanese traditional songs; Lemah Cai (Our Native Land), Dewi Sartika, Sinom Puspasari, among others. He was also a playwright and director of Sundanese music-dramas called 'Rinenggasari'; Sarkam-Sarkim, Satan Mindo Wahyu Revelation (Satan Personification as Divine Revelation), among others. As a music theorist, he formulated Sundanese solfage system da mi na ti la, and he wrote many theorerical publications on Sundanese music; Ilmu Seni Raras (Our Musical Art) (1969), Ringkesan Pangawikan Rinenggaswara (An outline of music theory) (1950), among others.