The font "Lucida Sans Unicode" is included with WinXP, and probably with some other recent versions, and is the one used in most Microsoft Developer Net articles for illustrating font manipulations in the Unicode character number ranges. It should be included with most default WinXP installations. It does include proper sharp, flat, and natural symbols, but they are "high number" characters that others may not be able to see if you post them.

Sharp:  U+266F       ♯
Natural: U+266E      ♮
Flat: U+266D           ♭

Those who have the Lucida Sans Unicode font can change their browser default font to it, and see if the symbols show immediately above, if they like. They do show in the Preview of this post, IF I change my browser font to the LSU one.

John