He was playing by ear
or
Your wife comes back to you, your dog returns to life and you get out of prison.
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No, but hum a few bars and I'll fake it.
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They can't find the key, and they never know when to come in.
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Root position cords.
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Seven. One to change it and the other six to sing about how good the old one was.
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He/She keeps trying to stick their fist up your butt.
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Take the pizza delivery sign off the roof
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Tell him the key signature has 8 sharps.
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Because they always ran around going "Bach! Bach! Bach!"
or