When it's Bluegrass it's Fiddle T-Shirt - Classic Heavy Cotton 

This Bluescentric Brand bluegrass t-shirt comes in classic heavy 100% preshrunk cotton sizes S-5XL. Heather colors are 50/50. Sizes run very true, and have minimal, if any, shrinking. This is a standard go-to t shirt.

It's not the instrument, bluegrass fiddling is mostly done on a violin, it's the way they play it! 

Once uttered by the great Texan Hank Hill, true fans understand that when you're playing bluegrass... you call it fiddle. 

This design was specially made for fans of bluegrass & fiddlers. It reads "When It's Bluegrass, it's Fiddle", with f-stop style swashes and a violin design.