Sustain allows you to extend the sound of each piano note. Sustain is turned ON by default and for most instruments the default setting is the most suitable setting. Some instruments which have naturally extended sound like the Organ, Violin, Pan-Flute and Accordion, you may want to reduce the Sustain level to -9 or turn OFF Sustain completely. When Sustain is ON, every key you press on Virtual Piano will continue to sound until it naturally stops. But Sustain can easily be turned OFF. Alternatively, the length of sustained sound can be reduced from the piano's Sound menu. When Sustain is OFF, the sound for each key is shorter. To make the sound longer when sustain is OFF, simply keep the key pressed for longer so that the sustained sound to can last longer. Once you've determined the instrument and Sustain Level that suits you, you can press the SAVE button from the menu which saves these settings so you won't have to set these settings each time you wish to play. To save your settings, you need to have a Virtual Piano account.