By default the value of a scale widget is changed either
by dragging the slider or by left-clicking in the trough. The
increment by which the left-click changes is the same as the
resolution, by default one unit. You can increase the increment
by which a click moves by increasing the resolution value (which
decreases the resolution in the normal sense). However, sometimes
it is convenient to have a finer resolution available while also being
able to move in larger increments. A solution is to bind to
<B3>, which is by default unbound, a larger movement.
This procedure moves by the specified multiplier k times
the resolution of the scale. 

 proc ScaleMoveBigIncrement {w k x y} {
    set part [$w identify $x $y]
    switch -exact -- $part {
	trough1 {
	    set dir -1;
	}
	trough2 {
	    set dir  1;
	}
    }
    set Resolution [$w cget -resolution]
    set CurrentValue [$w get]
    set Delta [expr $dir * $k * $Resolution]
    $w set [expr $CurrentValue + $Delta]
 }

The coordinates x and y are supplied by
Tk when the binding is triggered. w and k are,
from the point of view of the individual binding,
constants. They represent the scale widget and
the desired resolution multiplier. You supply
them when you create the bindng. A typical
binding might look like this:

 bind .play.vol <<B3>> {ScaleMoveBigIncrement .play.vol 5 %x %y}

Of course you can bind to some other event if you wish to.


[WJP]