 Each is laid out in a similar manner to a piano keyboard, except that pressing a key on a Hammond results in the sound continuously playing until it is released, whereas with a piano, the note's volume decays.No difference in volume occurs regardless of how heavily or lightly the key is pressed (unlike with a piano), so overall volume is controlled by a pedal (also known as a "swell" or "expression" pedal).The keys on each manual have a lightweight action, which allows players to perform rapid passages more easily than on a piano.