(most or all of these are not original)

What is a good sounding oboe? A clarinet.

How can you tell if a trombonist's kid is at a park? They can't swing and don't know how to use a slide.

My band teacher said he once saw a sign selling a oboe mute. Along with it was a picture of a hammer.

How many conductors does it take to change a light bulb? One probably, but really whose watching.  

What's the Difference Between a Tenor Sax and a Macaw? One is loud, obnoxious, and impossible to shut up. The other is a bird.

How Do You Know When a Tuba Player Is at Your Door? You don't. They can't find the right key and they don't know when to make an entrance.

What's the Difference Between an Oboe and an Onion? No one cries when you cut apart an oboe.

What's a Flaming Oboe Good for? Lighting a bassoon on fire.

What's the Difference Between a oboe and a Trampoline? You take your shoes off when you jump on a trampoline.

What's the definition of perfect pitch? When you toss a banjo in the garbage and it hits an accordion. 

Sorry to anyone this offends (if it does offend anyone). All of these are meant to be jokes. But thanks for reading I guess.