Mind you, that should not be construed as saying Signature Sound is bad. Just that they should stay in their lane.
The Cathedrals' bass singer probably shouldn't sing James Payne songs about coming from a life of drinking and drugs. Ole George ain't been there, so if he sang those songs they would come out flat. And James Payne should probably not sing Lecrae songs. We all have our own row to hoe.
But yeah, if you have to look up what shaped notes were, you probably don't know what old conventions were. (They were HOT, that's what they were. Air conditioning wasn't nearly as popular back then.)