Circuitry for generating rhythmic patterns of notes corresponding to notes of a selected chord wherein tone signals according to the notes of the selected chord are connected to the inputs of keyers each time a chord playing key is depressed and control a current which flows through the keyers to the organ output circuitry in accordance with a selected pattern sequence of notes which is provided to a plurality of envelope generators at a rhythmic rate. The keyers are grouped to correspond to the four components of a selected chord and each of the keyer groups has an individual envelope generator connected thereto which activates the keyer group under the command of the selected pattern and imparts a characteristic attack and decay envelope to the tone signal.
