4:5:6:7:9:11:13 chord

Best I could manage trying to get a 4:5:6:7:9:11:13 chord! The 11th harmonic is hard enough to zero in on and tune, but the 13th was basically a shot in the dark. I just played different clusters of already decently tuned notes to see if I could intuit when it “locked in“ with the rest. The other issue is that the piano is such an insanely poor representative of true harmonics to begin with. I did my best to tune everything to F below middle C’s harmonics, and only the lowest coincident harmonics in each case, so you can still hear all kinds of beating in the higher harmonics (ugh!).