How to Know Which Key a Song Is In

Which key is this song in? Which key should I solo in? What are the major scales?

How to Know Which Key a Song Is In
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I remember sitting up nights reading a lot of material trying to learn how to read a song, and find out which key a song is in, so that I might easily know which notes to base a solo on. But I haven't found any good guides that sums it all up, just some guides that seem to include some of the material. This is for beginners, to get a grasp of the subject.

So I thought I would write a lesson just for getting the basics down. I am a beginner myself(played guitar for just over a year now, and banjo for 2 months) and love playing guitar so this has become a passion for me.

Anyways, let's get down to business, shall we?

Let us see, let's take a song called "Me and Bobby McGee." The version I play uses the chords G, C and D. Therefore, this song is in G.

Now, why is the song in G?

Well let me tell you how I knew that, because it had G, C and D in it. Let me write down a chart:
key  1   2  3  4  5  6   7     
C C Dm Em F G Am B-dim
D D Em F#m G A Bm C#-dim
E E F#m G#m A B C#m D#-dim
F F Gm Am Bb C Dm E-dim
G G Am Bm C D Em F#-dim
A A Bm C#m D E F#m G#-dim
B B C#m D#m E F# G#m A#-dim
Now what can we see here? Well for startes, 1, 4 and 5 are always Major chords (G, C, F# etc). 2, 3 and 6 are always minors (Dm, Am, C#m etc) and 7s are diminished chords, even though sometimes used as a major in certain songs.

So, we have "Me and Bobby McGee," a song which as a G major, C major and D major chords in it. Look down the chart, which songs have G, C and D major in it? Ah, G has those three chords. Therefore "Me and Bobby McGee" is in G.

Lets take another nice country song while we're at it:

"Three Wooded Crosses" by Randy Travis

The version I know of this song uses these chords: C, Dm, Em, F, G and Am (and also Am7, but yeah). So, go up the chart and tell me what key this song is in. Scroll down when you are ready. Yeah, this song is in C.

Now, next song:

"Folsom Prison Blues" by Johnny Cash

It uses the chords E, B and A. Which key? Right, it's in E (as most of Johnny songs there).

Now the last song we'll look at is:

"Easy Come, Easy Go" by George Strait

This song used these chords: D, G, A, Em7, A7. (When facing 7's, just remove the 7). Now, this song is in D. Now you should have a clearer understanding of which songs are in which key. But, you are still wondering, why are i.e. G, C, Em and D chords in the G key, why exactly these chords?

And that is where Scales come in.

If you paid attention in music class in school then you will have learned the C major scale which is:

C D E F G A B (C)

Now this is a major scale, there are also minor scales but my knowledge of these are not sufficient to be teaching it. Now, you may or may not know that there are also sharps in a scale. So the full scale with sharps will be like this:

C C# D D# E F F# G G# A A# B (C)

This is the whole scale, notice that E and B does not have a sharp. The scale is made up by 12 notes. Which is also why you have a special mark on the twelfth fret of your guitar, if you fret the twelfth fret and play that note it is the very same note as the string unfretted.

The jump between say D and D# is called a halftone. If we were to jump from G note to A not, The step between that would be called a "wholetone".

One wholetone = two halftones (logically)

The "recipe" for a major scale is Whole:Whole:Half:Whole:Whole:Whole:Half. This refers to the jump between notes. Check it out:

C w D w E h F w G w A w B h (C)

w = whole, half = halftone.

The C major scale is the only scale without Sharps (#) or flats (b). Using the recipe from above, let's construct a E scale.

E w F# w G# h A w B w C# w D# h (E)

(We start at E, go up a whole note, that means jumping over F and straight to F#, then a whole note jumping over G to G#. And now, we just jump a half note, over to A. Then another whole to B, and since B hasn't got any B#, we have to go directly over C as well, landing on C#. Then it's another jump over to D# and a halftone jump back to E.)

Did you get that? Let's make a D scale using the same recipe:

D w E w F# h G w A w B w C# h (D)

Now, this recipe works for all the scales. There is a whole lot of information about this on Wikipedia if you just search of B major or E major etc.

Now, why are these scales relevant to chords? Well, because the C scale is in the key of C. And if you look at the notes you play when you play say a C major chord, you will find that you play the notes C, E and G (1, 3, 5). If you play a F major chord you'll be playing F, A and C notes. For the Am chords, you'll be playing A, C and E (1, b3, 5). If you were to play A major, you'd be playing A, C# and E. Which is why A major is not in the key of C!

Starting to see a pattern now? The G chord is G, B and D notes. These are all notes in the C scale.

Let's go back to the George Strait song, using the chords D, A, G and Em7.
  • D chord is D, F# and A (you're not supposed to play more than the bottom 4 strings when playing a D chord. The D string is the bass note).
  • G chord is G, B, D notes.
  • A chord is A, C# and E notes (1, 3 and 5)
  • Em chords is also G, B and E. A Em7 is G, B, E and D.
Sidenote: A little bit about how chords are built.

Major chords are built after this recipe: 1 3 5. Meaning that an G chord are the notes G(1) - B(3) and D(5). Just start from G in this case and count G(1), A(2) B(3), C(4) and D(5). C = C(1), E(3) and G(5). A = A(1), C#(3) and E(5). E = E(1), G#(3) and B(5).

Minor chords are assembled after this recipe: 1 b3 5. Meaning the third note is flat. Am is therefore: A(1), C(b3) and E(5) (C# flattened is C). Em is E(1), G(b3) and B(5). (Note: a seventh chord is 1, b3, 5, b7, b meaning flat 3 and flat 7).

Now for the Strait song, we've got these notes: G, A, C, E, B, F#, D. Line em up and we've got: D, E, F#, G, A, B and C#.

Now, scroll up and check which of the three scales we've cooked together adheres with this song. Yep, you're right. The D scale.

This eventually means, that you can solo on the song "Easy Come, Easy Go" by George Strait, if your rhythm guitarist is playing in key of D, then the notes D, E, F#, G, A, B and C would be considered "safe" notes to solo in. Even though it is safe to mix it up a little, these are ultimately the notes which you could base the solo on.

Well this concludes my little lesson, hope you found it helpful and if there should be anything you need to ask about, please post a comment. Also if you have any comments about the lesson or corrections, please do not hesitate to comment, just don't flame me, I am a beginner myself.

75 comments sorted by best / new / date

comments policy
    eatfresh1736
    HansFredriksen wrote: Yeah pretty sure it's still in G. As long as the major chords used cohere in the chart. The thing is, and I haven't gotten to that yet, there is something called minor keys as well. So I am not entirely sure if G, C, D is exclusive to G major, and not say E-minor(which would be my guess). But it was a coincidence, I find it easier to remember the chords in order of G, C, D because it correlates to the 1, 4 and 5 chords in a key.
    I salute you, sir! You've got big balls to write an article about music theory when you don't know much of it yourself. People who play rock often think that theory isn't important. I myself play metal and I'm trying to break the stereotype that metal guitarists are musically retarded. One thing that I have to mention is that the minor scales are equally as important (if not more so) as the major scales. Once you start learning more songs, you'll see that most rock songs are written in minor keys. Good luck with your theory!
    HansFredriksen
    Okey, I read through it and thought it looked good though, but I found a few minor errors. I'm not from an english speaking country though, if that counts for anything. Heh, noticed just a moment ago, I do use the word "now" a little too much. I wish there was an edit button.
    rockingamer2
    Find out what chord the progression feels resolved at (where it feels "at home"), then look at the progression from there. Keep in mind that the first and last chords are often not the key of the song.
    enslaved13
    @HansFredriksen Hey man I love your article it's very well set out. I'm starting to learn the Music Theory, and I by accident stumbled onto your lesson. I can play a number of songs from Amon Amarth and Metallica however I tried to figure the Key of Seek and Destroy by myself but after I thought it was in G I read on the internet that it's in E-minor, would I still be using your chart up there or is there a different chart? Because it might just be me but I can't seem to work it out so to see that it in fact is in E-minor! How do you go about taking a song and then working out the Key it's in? (like which steps do you take)
    Reyes2511
    They teach most of this in most any guitar theory book. What you taught at the beginning is called a "Chord Scale". You create a "Chord Scale" that you use as a chord progression (In turn also being the Key of the song). Generally, a chord scale is a series of chords named in a scale USING the notes in the scale to create the chord.
    key 1 2 3 4 5 6 7 C C Dm Em F G Am B-dim D D Em F#m G A Bm C#-dim E E F#m G#m A B C#m D#-dim F F Gm Am Bb C Dm E-dim G G Am Bm C D Em F#-dim A A Bm C#m D E F#m G#-dim B B C#m D#m E F# G#m A#-dim
    This is an example of the various Major chord scales. Then bands usually use a "I-V-IV-I" to describe their chord progressions, and if you look at the Cmaj that this type of progression would be: C-G-F-C.
    theo.lawrence.1
    Good work on the article

    I am currently making an ongoing database of 'songs in the key of'. For those times when you just want to solo along to some songs without doing the theory, this might be useful to some of you. I recommend learning how to work the key out yourself in addition to this, but sometimes you just wana put some music on and jam along. Here is the website:

    http://learnguitarforfree.com/songs-in-t... Keep up the good work.

    Theo Lawrence / TL Music Lessons

    P.S. I'd also like to share my method for working out the key of any song just from listening to it:

    To be able to work out the key of a song, I have studied the major and minor diatonic chord theory, and the visual patterns of where the root notes appear on the fretboard for these. The most useful resource I found on this topic is on the Justin Guitar website here:

    http://learnguitarforfree.com/songs-in-t... With this knowledge ingrained, I listen to a song and start to play root notes on the guitar of the chords that I hear. If I recognise the pattern, I might try a major or minor scale in the key I suspect the song is in. Sometimes I'll test this further with chords...

    When I start to notice a familiar pattern in the root notes, I will try to convert some of the root notes to barre chords in those positions. This is where the diatonic theory comes in.

    e.g. If the root notes are G, A, B, C, I might think its in G major because they are the 1st, 2nd, 3rd and 4th notes in the G major scale. Personally I would usually just follow the pattern rather than thinking of the notes. So, I would then test my theory by applying the knowledge that the 1st and 4th would be major, and the 2nd and 3rd would be minor. So, I'd try the following chord progression: G, Am, Bm, C. If this fits with the music, I'd then try out a G major scale over the top of the music and if it fits, it's likely to be in that key. Sometimes I'd skip the step of testing the chords if I'm fairly certain of the key of the song just from the root notes.

    You can also listen to the start and ending chords, sometimes that is an indication of the key.

    There are a few other things that can catch you out like knowing if a song is in F# or Gb. Studying the ebook from Justin Guitar will help with these things too. The main rules to remember are, you can only have 1 letter in each scale (i.e. not B and Bb), and you can only have sharps OR flats in any given key.

    I hope this helps.

    eatfresh1736
    JediRabbit wrote: What if I'm writing a song that I want to be in the key of C, but I decide to use the Chords C, D, E, as opposed to C, Dm, and Em. Is it still in the key of C?
    That wouldn't fit in any specific key. You should look at the notes in each chord and find the key that fits it most. With C, D, E, your best bet is G major or A major, and the odd note(s) out is called an "accidental" note - even if it was on purpose.
    W.Latruno
    This is very helpful ! I sure hope there is a part II on Minors in the works. Great feedback/comments too.
    burndttoast
    Pretty good article from what I read so far. The only gripe I've come across is that you use "now" a bit too much--just get into the content. Question though (you may or may have not answered this: I didn't finish the article cuz I'm at work)-- does it matter what order chords are used? It's still the same key right? For example, a song has the chord progression C, G, D. Is it still in the key of G? I only ask because the examples you posts listed the first chord as the actual key, so wasn't sure if that was coincidence or not.
    krypticguitar87
    you also got quite a few spelling errors, as much as I hate being the grammar nazi, I hate seeing errors in lessons and columns more.
    HansFredriksen
    I use the chart mostly, yeah. I identify which 3 major chords are in a song and go from there. But hey, there are some charts out on the internet. Just google "key chord chart" and this one came right up: http://www.ezfolk.com/uke/Tutorials/1fou... /key-chord-chart/3-key-chord-chart.jpg Here you have an overlook of the minor keys as well Good luck man!
    mattiwillohouse
    this is a decent article but why do you talk like a children's TV presenter? 'now what can you see, that's right! a red bus!' 'What do we have here? Let's see, a hungry beaver!' LOL
    aibooklang
    thanks for the idea u have given to me…it realy help me..but i have some question..i can undeerstand and use only the major and minor chords..what about the 7,aug,dim,etc…how to use them?…which one is hhigh and which one is low?…please nate help me with this….
    gerharddvs
    Dude, I solute you. After asking many people. Your the first person I've found that explains this in a way that makes sense. Shows if you want a good simple explanation on something, don't ask a pro but a novice that had to figure it out for them selves...
    HwyStar
    What about a table that has all of the sharp keys? As in C#, D#, F#, G# and A#... Do these keys have a similar table of chords that relate to the key?
    driveme2phirenz
    This is a very thoughtful and well-organized article for other theory beginners. I found a lot of other resources to be intimidating or overwhelming, but this yours was very straightforward and easy to understand. Thanks and well done!
    sharunyxox
    ok, what about if a song also uses chords like Dsus4 amd Cadd9, but still has Am,Em,G,D,C,E? what key would that be in?
    hankabuldank
    Dsus4 and Cadd9 are variations of D and C. A chord chart can show you how to finger them. The key is the one that has the basic chords you listed, probably G. Think D and C instead of D(variation) and C(variation). Note that you cannot have a minor suspended chord (because the chord suspends/removes the third and adds the fourth instead), but you can have a minor add9 chord. Good luck!
    theo.lawrence.1
    sus4 and sus2 chords can be in the place of a major or a minor chord. Yeh that's probably in G. G, C and D are the 1, 4, 5 major chords, and A and E are the 2nd and 6th notes in the G major scale, so would be minor (Am and Em). The E chord is the red herring in this list, by breaking the diatonic theory rules. Playing notes and chords outside the key is normal in songwriting, and is something to watch out for when working out the key.
    strahil.vasilev
    really nice lesson man,but now i have 2 questions...First if the song have the chords: Am,C,F,E the song have to be in the key of C ? And now one very important thing if the song is in C or D or G key what scale i can use to do a guitar solo ?? Please answer it's important to me! Thanks
    HunterMorrison
    so ive written a song thats all finger picking.. the riffs are all on one string at a time..( btw i am new to guitar so bear with me ) so im wanting to write the chords for it.. how do i figure out what key the notes im playing are in so i can match the chords to the notes?
    boolong
    The key of a song is the chord it would want to end on (and usually but not always, does) If you've an ear for musical resolution you can ignore all the above theory and listen for the chord the piece wants to end on.
    un4toldsins
    Learn the role intervals play. 1 half step=minor second 2 half steps=Major second 3 half steps=minor third 4 half steps=Major third 5 half steps=perfect fourth 6 half steps=augmented fourth 7 half steps=perfect fifth 8 half steps=minor sixth 9 half steps=major sixth 10 half steps=minor seventh 11 half steps=major seventh 12=octave This will help distuingish if the key is major or minor. Take "Polly" by Nirvana. First chord is Em....then G On your open E string count out the steps from E to G. Three half steps is a minor third. Then E to D....10 half steps....Minor seventh E to C....8 half steps....Minor sixth Key has to be a minor.
    gak2936
    What if a song is played with the chords: Cm Fm and C sharp ? I couldn't find the key in the Chart.
    NeoMvsEu
    Cm, but for more clarification - having both i and #I is bad practice. In theory, it'd be Cm Fm Db (i iv bII). This is a beginner article. Chords outside the key, like Db (bII), have their uses, but they're non-diatonic (not in the scale).
    sourabh1238
    very impressive. too good article for a guitarist whose started playing 1 year ago.
    jami74hashmi
    wao amazing post Guitar Pro 6 really nice work. keep it up . i appriciate you with all of this . i bookmark your site, it really amazing and having a much more knowlege for me . i really appreciate you.
    gspriggs
    Nice job, ignore the critics. Been playing along time and its always good to revisit theory. Anyway just wanted to say I picked a tune of the top of my head (Jimi Hendrix "Hey Baby"). Well, he breaks the rules right away. Just remember that the real reason we play is because we love the way good music sounds. The real theory is ..."how does it sound to you", if it sounds good, your theory is good. Beginning of song Am, G, F, Dmaj(what? where did that Dmaj come from?... sure sounds good though). Still in the key of Am. Now the chorus Amaj, Db D (really...where did that come from), but it sure sounds good. You break the theory rules and you get more tension and release / resolve. That's a good thing at the right time....
    few_chanhom
    Most of the teachers don't want to teach this. Thank you so much for the information
    sekm
    I use a website called whatsmykey.com It doesn't get the key right all the time (95%) and it only gives the main key of the song (i.e. doesn't pickup the changes), but it's pretty helpful. You can upload mp3s to scan and get the results too.
    dspangler86
    I didn't read through every single comment, so I apologize if this has already been mentioned. But a little trick that I have always used to determine a minor scale, is to find the 6th note in a major scale and simply start the scale there using the same notes. This is referred to as a "relative minor." For example: a C Major scale C D E F G A B C Now if you were to start on the 6th note which is "A" you would form an "A minor scale". The note pattern looks like this: A B C D E F G A... In reverse you could also say that the 3rd note in the minor scale (C in this case) would be the major scale which is relative. Hope this helps.
    smigger22
    Great article, really helped me out a lot, still new to music theory and we are not at that stage yet in school (6th grade for the Americans, Year 7 for the British) and as a metal player, it has really helped me make harmonies, solos and rhythm parts. You sir, have earned my respect.
    gak2936
    I've read this article and did understand it, but half of the way i lost the plot. But i think it was easy enough for me to follow you. I will get back and read it again and use your method finding the key, which is the most complicated puzzle and worrying thing for me right now, see if i can manage that. Thank you and best regards.
    k0stil
    It's also depends on with which chord you start. You can have G, C and D and it can either be in the key of G or in the key of D. If you play it: G C D, it's in the key of G. If you play it: D C G it's in the key of D. (it's the chord progression used in the end of hey jude, although hey jude is in F, so it's F D# A#)
    HansFredriksen
    marlonn wrote: when u line up the chords in strait song how come D is in the first line?
    Sorry for late reply, it is totally coincidental that the first chord I list is the same as the Key, but if you look at a lot of country songs, most of them actually start with the Chord that the key is in. But this is not always true for songs in other genre's I've found.
    meeler3
    meeler3 wrote: You started explaining using a 'key' chart and then went to scales (the scales explanation makes sense, btw), but what is the difference between key and scale, and is there a similar pattern or rule of thumb about keys (ex: the key of C)?
    As it is obvious, I am just starting to learn music theory. I understand the circle of fifths, the w-w-h-w-w-w-h, and circle of 4ths, but am finding it a little but more of a challenge to connect the dots of a lot of other stuff. I guess I need to try to study all I can get my hands on. It just threw me off to see the key of C using non major keys - C C Dm Em F G Am B-dim Thanks
    JediRabbit
    What if I'm writing a song that I want to be in the key of C, but I decide to use the Chords C, D, E, as opposed to C, Dm, and Em. Is it still in the key of C?