What would win in a contest Edwards or shires trombone?

It's impossible to say definitively which brand of trombone would win in a contest, as different players may prefer different instruments for different reasons. Edwards and Shires are both highly regarded brands of trombones, and each has its own strengths and weaknesses.

That said, some general comments can be made about the differences between Edwards and Shires trombones. Edwards trombones are typically known for their rich, dark sound, and they are often considered to be good choices for classical music. Shires trombones, on the other hand, are known for their bright, powerful sound, and they are often preferred by jazz and big band players.

Of course, these are just generalisations, and individual trombones from each brand can vary significantly in terms of sound quality. Ultimately, the best way to decide which brand of trombone is right for you is to try out different instruments for yourself and see which one you prefer.