I haven't studied the machanics of why reeds go flat when pushed hard, nor how you can compensate for that by adjustment. Next time I see Steve Dickinson I'll ask him. I know it can be done: the (non standard) bottom G on my melodeon was sharp when I bought it but went nicely into pitch when squeezed hard, then when Nils Neilsen had a go at it he put it in tune and it stays in tune under pressure.

Bob: thanks for the details on "Kneller Hall" - I know it's what we called "old pitch" and I suspected it might have had something to do with brass bands and related intruments.

Wandering off topic a bit - yes, tuning a guitar down would make a mellower or weaker sound. Usually such effects are achieved by selecting strings of a heavier or lighter gauge - heavier strings need more tension for the same pitch. (Bit out of my depth because I don't actually play guitar either)

As for steel framed pianos - I guess there's lots of reasons for different sound. Steel would be more rigid and absorb sound energy less than wood so it would sustain better, and it's the higher frequencies that would be absorbed most, hence a brighter sound with steel. But for all I know higher string tension might help too.

Anahata