The "problems" with bad tuning are from nature and are due to whoever/whatever created life and the basic principles of the harmonic series. PLEASE DO NOT BLACK LIST THIS COMMENT. This is a fact of life that we manufacturers must accept. We cannot change, for instance, the fact that the 5th harmonic is flat in comparison to the tempered scale. My idea of design is to create such clarity of feedback to the player that pitch compensation is so automatic that they do not realize it - rather they say "Wow, this trumpet is so well in tune" Yes there are devices such as the Jack Holland Pitchfinder which enable the player to lower and raise any note. But the trumpet playing public to a large degree do not want these devices (as evidenced by the fact that there is a large stockpile of these at the home of the inventor's heir). Players want to get their low D and C sharp in tune but not their fourth line E. Merri Franquin had a wonderful design C/D trumpet (which Roger Voisin played for years) which essentially negated the use of anything longer than 2 and 3 valves (imagine not having to use 2 and 3 for high A flat!), but it, too, died. There have been attempts to revive it, the latest being by Clifford Blackburn for David Hickman from concepts drawn up by Bryan Ewing, a DMA student. This 5 valve design appears to be quite clumsy. I have started making a 4 valve C/D, based on my quarter tone C, initially for my own use.