STS button "solid light" it always picks sts #1 when you change to a new style ( stays on sts #1 even if you change to variation 2,3 or 4. STS button "light flashing" it will change to sts 1,2,3 or 4 depending on which variation you are using. STS button "no light" whatever sound you are using will stay that sound no matter what style or variation you are selecting.