A copy of the Sherman & Hyde Musical Review (San Francisco, 1874) came across my desk and I happened upon this "artikel" written in tongue-and-cheek defense of the shape-note singing technique (aka, "skuare notes"), which was apparently looked down on by 'properly trained' musicians--"Round Heds", who read music with the standard round-head notation. The Music Library has a number of of shape-note singing primers, which were the subject of a 2012 exhibit on Early American Tune Books. Several titles have been digitized; see The Easy Instructor for examples of shape-note notation.