When I use Bandstand as a stand alone program this button does not appear. When used with another program like PgMusic biab or Realband. This little botton appears just to the left of play in the Mixer window of Bandstand. I've looked in all my Bandstand documents and can not find any explaination of what this buttons function is. When used in biab the button is lite up. When used in Realband it is not lite up but will light up if activated with the mouse. But what is this little button suppose to do ?