Parentheses

[Urs Liska]

Hi,

can you tell me what the \parenthesize function uses to print the 
parentheses?
There are paren glyphs in the accidentals section, are they used for 
that purpose?
And does this mean that I can only resize parentheses proportionally (by 
using a different font size)? Or is there a possibility 'stretch' them 
when the surrounded object is taller?

Thanks for any input
Urs