in piano sheet music, what is the purpose of the squiggly line on the left but outside of the staff system?

Question

It looks like it connects the g-clef and base clef and somewhat resembles this: {

Answer 1

It just links them together so you know they are read simultaneously. There are times when it will be written on only one staff. Anyway, this is mostly for the sake of clarity, especially when in a score with another part.
And that's treble and bass clef, kiddo. This from someone who reads alto clef. >_<

I also find it amusing that JF and I used the same word...simultaneously. ^_^

Answer 2

That's exactly what it does. It tells you that you play the bass-clef part with the treble-clef part simultaneously. It's just so that you don't play the treble-clef part first and then go down to the bass-clef part and play them separately.

Answer 3

Its the grand staff line...it connects both staffs together...into the grand staff...