Hi George, and welcome to Vista Forums.
The Index only runs slowly in the background to update itself when the computer is idle or at low usage. It may not have had time to finish updating the index list yet to include the D:\Music files. You can
rebuild the index to force it to update faster.
In the Advanced search window, you could also check the
Include non-indexed locations box for a more accurate search result to.
Hope this helps,
Shawn