How serious is a crack in an oboe`s top joint? If it`s been professionally pinned, does it still affect the sound?

It really depends on the type of crack, how long it is, and how well it was pinned. If the crack goes all the way down to the bore, that might be a permanent problem. If it`s just a hairline that was caught early, that`s often not a problem.

The real problem with an oboe that has cracked is that you know automatically it`s been exposed to radical changes in humidity, meaning the wood has been stressed all over--not just at the crack--and that could pre-dispose the oboe to crack again in the future, especially if you are importing the oboe from a humid climate to a drier climate or vice versa.

What specific affects does a crack have on the sound? I suppose the integrity of the instrument would be compromised, causing it not to resonate as well, and maybe lose some colour or depth (just guesses).

If anyone has had an oboe that has developed a crack, have you noticed any changes in the sound quality?

I have had my oboe crack in two places one on the key side that went in the trill keys and one on the back which didnt do threw anything. my oboe sounds and plays the same and most oboes dont sound diffrent unless it goes all the way threw or if it cracks the tone holes in a odd place. Many wooden oboes crack and many crack again its not a big deal if you get it fixed buy a pro.