A fairly thorough search at Microsoft finds no reference to the Symusic font. A Google search finds it identified as an "Autodesk font" so I may have gotten it with my AutoCad LT. It does appear in a large number of "font packs" available from a number of sources, and may have been used in any number of add-on programs; but so far as I can tell "generic users" are unlikely to have it.

John