So, no more F7 for awhile. (Oops, wait, no. It’s just F.) I need A7, B7, D7 and E7 for Another Blues Riff, a strummed one this time, that the IA sent me yesterday. I tried all four of them separately tonight. Each one sounded like a bag of cats, just swung at varying speeds. Conclusion: I am nowhere near this thing, and four new chords at once was a ridiculous thought. D looks manageable, on first fingering.
Conclusion the Second: I should not try to tune my guitar, any guitar, by random fits of intuition. I couldn’t hear much change in each individual string as I tried to figure out which way to turn the knob, but even these ears could hear that familiar chords sounded worse than ever. Bags of cats being, say, nudged repeatedly across a hardwood floor.