John, would you post a URL? I suspect you are just talking about shape notes (and bad resolution) Shape notes come in square, diamond, triangular and round. The idea behind the notation is that even if you can't read the note or key you will know what part of the chord it is. It was a way music was taught in this country beginning in the late 1700's, It began in New England (with Joshua Billings among others) and then spread south where it still is alive today.
Classic shape note tunes include What Wondrous Love and Precious Memories, Rocky Road, Bound for the Promised Land. Most of the tunes in Sacred Harp are named after places (Idumea; Concord) and many are contrapuntal (fuging tunes). The one everyone knows, fuging part goes "Fly swift around ye wheels of time (2x) and bring the promised day", I can't remember its name right this moment.
Start a thread asking about shape notes if you want more of an explanation. My memory's rusty.
Blessings,
Barbara