Theory; finding what key a song is in (need help).
 

Hey there, this is my first post, so don't go too hard on me.
I just started learning music theory on my own; I play guitar, for the most part. I taught myself modes... learned intervals from a guitar teacher back in the day... and know the major scale, minor scale(who's even counting that), and pentatonic scales (same with that). So, as you can see, I don't know much music theory, haha :)

That's why I've searched for help! :shycouch:

I've always asked my friends, that play music as well, how to tell what key a song is in... none of them ever give me a theoretical explanation. Some said whatever chord is played the most... YEAH RIGHT!... is what I thought to that.

So, with that said... how does one know what key a song is in?

This is my hypothesis, with little knowledge of music theory I have...

Whatever major scale the song is in; the root note of that scale is the key of the song.

Is this right?

Anyways, thanks to anyone who can be of some help towards this!

Easy days

Yeppers.

the root of the last chord of the song will be the song's key most of the time

the key sig will also tell you

heres a helpful link

MyGuitarWorkshop

If you want to get deeper into theory and finding keys (which isn`t always as straightforward as suggested) try looking up the Circle Of Fifths on wikipedia. Print out the Image, you can see how different chords and scales can be connected - thats only one approach, theres different ways of looking at it - plus playing differrent types of scales (as you`ve mentioned) with the same tonic will give a song many different `feels`.