Where to get an icon set for sheet music? [on hold]

I am looging for an icon set for my a software which helps to organize sheet music (currently in development). The user interface is made with bootstrap and uses some glypihicons. So the icon set should fit to the gylphicon style.

The icon set should contain icons related to sheet music, e.g.:

• songbook
• single piece of sheet music
• band
• instrument

Where can I look for such an icon set? Or, if there is no such icon set available out there (for free or not for free): What are recommended ways to get a designer to build this icon set?