Ours has changed some, but not drastically.
This has been our official badge since 1910:
The original badge looked like the current one except the Greek letters (and the lines separating them from the "S") were absent, and as a result the "S" was larger. This, of course, reflected the fact that our name originally was simply The Sinfonia Fraternity. I think that rubies may have been used instead of garnets.
In the early 1900's, a desire arose to include the Greek letters, which were being used in other contexts, in the badge. Around 1905 or '06, the triangle was turned point-down and separated into four triangles (formed by placing a point-up triangle in the center, its points touching the middle of the lines forming the larger triangle). An "S" was in the center triangle,
F was in the upper left triangle,
M was in the upper right triangle, and
A was in the bottom triangle. (Sorry -- I couldn't find a picture on-line.)
In 1910, the triangle was turned point-up again, and the current design was adopted.
For many years, a non-jeweled badge was available, but the jeweled version remained the official badge. At our National Assembly last year, we voted to make the jeweled version the only one available. The placement of the pearls and garnets cannot be altered.