The register key is at 4.5 inches and the first tone hole is at 14.5 inches. At the register hole the 3rd and 5th harmonics are at a node, while all of the other harmonics don't appear to be at any extreme. The odd harmonics are all at a peak for the first tone hole, while the second and forth harmonics are approaching a peak at that point. From this note on, there are low even harmonics outside of the clarinet.