I have an old harmonica and i dont know what key it is in, how do i found out?

It doesn't say anywhere on it.
Harmonicas don't have keys?

Are you thinking of a "piano"?
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Quote by Austin_Scharosc
Harmonicas don't have keys?

Are you thinking of a "piano"?

Harmonicas are in one specific key e.g. C , A or E.

EDIT: ^Beat me to it.
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Quote by blynd_snyper
What note does your guitar tuner give you when you play hole 1 blow? That's the key it's in. (I'm assuming you're talking about a diatonic harmonica.

Ya, its in C thanks. I wasnt sure if the key was the note i blew into or inhaled into.
Quote by moody07747
...Im not sure, probably by the first note it starts with...(at the low end...)

and if that is true a guitar is probably in the key of E....................?

Honestly? Honestly? Guitar in the key of E? HONESTLY?!
Edit: to be a little more helpful though a guitar is just like a piano in a sense and both are in the key of C.
We often feel sad in the presence of music without words; and often more than that in the presence of music without music -M. Twain
Find out what the note is on first hole blow and thats it. Piano and guitar are in Concert C pitch (it's a very long story, look it up on the googles).
blow in it over a couple of holes

it'll play a major chord of the key in it

then match with your guitar/piano/whatever