Our forge item for this month is a traditional triangle dinner bell. There is a lot of information available for working backwards from the desired note to the size of material.

There's also conflicting information out there: tight bends are better, loose bends are better . . .
One interesting point is to hang it from a point 22.4% of the length to maximize the sound (that would be: multiply it's length by 0.224 and bend it there). That's worth experimenting with!

Here's two of the more interesting sites that I found: Please let me know what you find out that works out of all the confusing things out there!

anvilfire discussion (click here)
website on designing wind chimes (click here)