Posted on January 10, 2010February 7, 2024 by Dale Phillips Questions: Fret Shape and Tonality Questions: Fret Shape and Tonality by R.M. Mottola Originally published in American Lutherie #76, 2003 R.M. Mottola of Newton, MA answers Earles L. Mc Caul’s question regarding the effects of guitar fret shape upon intonation and tonality. The short answer is no effects whatsoever. There is a good (but highly technical) article on this subject by Steve Newberry in The Big Red Book of American Lutherie Volume Two, p. 106, “Fret Crown Radius: A Cause of Pitch Error?”