“Valve alignment” is obviously meant to be a correction/adjustment of the ports/liners in the valves to obtain a smoothest possible transition between the valves and tubes/slides. When thinking about acoustics and standing waves, I am not sure that we actually talk about “smoothest possible transport of air” but I tend to think more like “smoothest possible transport of the standing wave”. As an example: I bought an old Couesnon flugel, which had an extremely “tight” resistance when I tried it with open fingerings. This “tightness” opened up when I pushed down the valves. The more valves pushed down, the more open sound. The short stroke of the valves made me suspicious, and when I took out the valves, there was three (3) felts under the cap. The misalignment was appr 3mm which covered 30-ish percent of the passage through the valves. Removed two of the felts, the valves came back to their original position again (95-ish%...)and the horn started to play again. So, what about this “smoothest possible transport of the standing wave theory”? My idea is that in this (my) case, the wave was disturbed (reflected?) by the extreme obstructions/surfaces it met on its way through the “acoustic area” in the horn. When the obstructions was removed, the wave could operate freely again. Just some philosophical poetry?