A comparison of the level of abdominal muscle activity and the movement of the chest and abdominal wall during the opening bars of the first movement of Mahler’s 5th symphony performed in different postures by a professional player. Muscle activity reaches much higher levels than for the excerpt in Figure 6 reflecting the higher pitches and sound intensity generated. Activity is greatest when standing and lowest when sitting on a flat seat. Sitting on a sloping seat results in an intermediate level of activity. There is no consistent difference between chest and abdominal movement in the three postures.