Assign categories to subsection, the create list of categories (like list of figures)

Assign categories to subsection, the create list of categories (like list
of figures)

Basically I'm using LaTeX to organize my sheet music. Each piece of music
is a subsection, which shows up in the ToC.
What I would like to do is assign a category to each piece of music and
then organize these categories in a "List of Categories" at the front of
the document much like the "List of Figures".
I haven't found a way to do this, and am wondering if this community could
help. I'm competent with LaTeX but am not experienced with making my own
commands. Hoping there's a package that could help with this.