I may be missing something here. The purpose of a slider is to set a
value. The position of the slider is a graphical representation of
that value.
>> indeed, this is a separate issue: essentially ensuring that there is a
We are getting into the realm of specific use-cases. I don't believe
it is possible to write one perfect UI element to handle the setting
for gain, frequency, scale position, and all the other things that
have values relevant to making music.
The slider discussed originally, with a graphical element and the
ability to define specific numerical values via keyboard has a lot of
merit and is useful in many situations. The fact that it has
limitations is quite normal, and is true for just about everything I
can think of.
On a related note, the probability that a potentiometer can be set to
exactly the same resistance twice is close to zero. This does not
make potentiometers less prevalent in musical applications.