Raden Machjar Angga Koesoemadinata (often written as Kusumadinata, Kusumahdinata, Kusumah Dinata or Anggakusumadinata), known as Pak Machjar or Pak Mahyar, is a Sundanese music composer and an Indonesian musicologist, specializing in pelog and salendro.
He invented the Sundanese solfège system (da mi na ti la) and the Sundanese 17-tone model.
He was born in Sumedang on 7 December 1902, and died in Bandung on 9 April 1979.