What Are I IV V (1 4 5) Chords and Why Should You Care?

What I IV V chords mean and why you should care about them.

Ultimate Guitar
If you hang around musicians for long enough you'll start to hear them talking about numbers and in particular the chord numbers 1 (I) 4 (IV) and 5 (V). You may be wondering what they mean as you may know the chords AD and E but don't know how to play I, IV or V chords. 

The numbers IIV and V come from a musical relationship called harmony. It might not sound very cool but music is based on maths. If you can get your head wrapped around some of this math learning songs and writing your own songs can be easy and less mysterious.

The numbers I, IV and V refer to the 3 main chords used in many blues, rock/pop songs and how they're related to each other and work together. To explain this further we're going to learn some basic music theory. The numbers used in music harmony (how chords work together) are based on the steps of the major scale. Below you'll see the C major scale with each note labelled with a number in Roman numerals. Roman numerals are the convention used to write the numbers for the chords in music.

Next we'll create chords by stacking extra notes on top of the scale notes. These chords are called triads as they use 3 notes and the extra notes added are called the 3rd (note) and the 5th (note). Creating more numbers to worry about! The notes used to create these chords come from the C major scale. Doing this you'll see that some chords are major and written in capital roman numerals (e.g. IV & V) and some minor written in lowercase (e.g. ii & iii).

The I chord is called the tonic or the root chord and acts as the home base in a song. A song usually ends on the I chord as it feels comfortable just like going home. The 2 other chords that act as big signposts pointing to this "home" chord are the IV chord (called the sub dominant) and the V chord (called the dominant). The V chord resolves to the I chord which means that if you play a V chord in a song followed by the I chord it sounds like going home to rest.

See how this sounds by first playing a C chord to establish the tonic (I) chord then play a G (V) chord then play the C chord again. This should sound like going home or the end of a song.

Listen to the audio example to hear the C (I) to G (V) to C (I) chords here.

Try this also playing the C chord (I) followed by the F chord (IV) then the C chord (I) again. This should to sound like going home but not as strong as the G (V) going back to the V (I). Think of it like gravity making objects fall to the ground with the V chord being heavier than the IV chord like a lead weight falling faster than a feather.

Listen to the audio example to hear the C (I) to F (IV) to C (I) chords here.


So now we have an idea of how these chords work together we can look at how they work in songs. While many songs use I IV V chords the trick is that they're often in "different keys." The term "key" opens up a whole new can of worms as we are now have to look at the major scale but starting on different notes. 

The major scale has a particular sound based on the steps or "intervals" between the notes. These intervals must remain the same whether you start your scale on C, G or A notes etc. A whole tone (W) is 2 frets apart on a guitar and a half tone (H) is 1 fret. The note intervals of a major scale are W W H W W W H. To make the scale fit this interval pattern we have to make certain notes "sharp" (up 1 fret with the # symbol) or "flat" (down 1 fret with the b symbol).

For example for the key of G major the note F needs to be changed to F sharp (#) up one fret to fit the pattern. If this isn't done and the F note is left as a "natural" note the scale doesn't sound quite right. Also if this isn't done and we create our triad chords on the notes of the G major scale the V chord would be D minor and not D major. The D minor chord does not resolve strongly to the G chord like the D major chord does.

To hear this play the G major chord to establish the tonic then D minor followed by G major.

Listen to the audio example to hear the G (I) to Dm (v) to G (I) chords here.

Next try this again but play D major instead D minor and it will sound more like going home finishing on G major after D major.

Listen to the audio example to hear the G (I) to D (V) to G (I) chords here.

Looking at the diagram above you will see that the I IV V chords of G major are G, C and D major. I like to call these 3 chords the chords of country music as heaps of country songs use these chords including:
Below is a table showing the I IV V chords for some of the most common keys. You can use it to work out the I IV V chords used in heaps of songs.


Now we know what I IV V means and how it works as a formula used in may songs the next use for thinking of chords as numbers is being able to "transpose" or change songs into different keys. Sometimes a song isn't in the right key for a singer meaning that its not comfortable for them to sing as certain notes are too low or too high. Therefore the song needs to be transposed to a key that better suits their vocal range.

To do this use the table to work out the I IV V chords for a key that suits them best. For example they may struggle to sing "Wild Thing" in the key of A (A D E chords) but may be able to hit all the notes in the the key of D (D G A chords).

Here are examples of I IV V songs in their original keys:
  • "Bad Moon Rising" by Creedence Clearwater Revival - I IV V in the key of D = D G A Chords
  • "La Bamba" by Richie Valens - I IV V in the key of C = C F G Chords
  • "Summertime Blues" by Eddie Cochran - I IV V in the key of E = E A B Chords
  • "Steal My Kisses" by Ben Harper - I IV V in the key of G = G C D Chords
  • "Wild Thing" by The Troggs - I IV V in the key of A = A D E Chords
So now you know how I IV V chord harmony works, what songs they're used in and how to transpose songs between keys.

28 comments sorted by best / new / date

    But If there's no tabs, how can the UG community possibly read this strange configuration of music??
    Agreed. I can't read this shit. Where's my numbers and little lines?
    Trying to figure these out on your own will make you a better musician and guitarist.
    i do agree with kostas but "strange configuration of music" was a funny shout.
    'Think of it like gravity making objects fall to the ground with the V chord being heavier than the IV chord like a lead weight falling faster than a feather.' no no no no! no! heavier objects do not fall faster... Still, useful lesson.
    To say that Dm does not strongly resolve to G is limiting the usage to only the key of G. If in the key of C the Dm becomes the II chord and works very very well in the II, V, I resolution of many a classic blues tune. Not all resolutions require going from chord X to chord I within a given key. Some resolutions create elaborate setups and emotional tensions vital to making any song more than just a simple tune.
    While it isn't untrue that Dm can resolve to G, there are a few things to be added to this notion. For one, it doesn't resolve strongly to G. It can resolve, certainly - but it does not do so strongly. There is a definitive urge one feels in a V - I cadens, and this is because of the leading notes that are present in these chords. A V7 - I progression even has two of these, specifically the 3rd and 7th of the chord. These dissonances are notes that want to resolve because of their relation to one another, a minor 7th in this case and creating a tritone(and if you play metal, probably your favorite interval in all existence). Leading notes wish to resolve, and dissonances wish to resolve. This is why we use them in that manner. A Dm - G cadens has neither of these, so while it can resolve there is no particular urge for it, since the Dm hasn't the leading note (F#) that the D has. Now, had we been in G-minor as a key, we might have played a Dm-5(using a Dm with a b5, I'm specifically noting it as this since there are some translation issues in this) - G as a II - V, now there are dissonances. There is tritone relation between the root(1st, tonic) and the 5th (of the chord) that wishes to resolve. That is a strong relation, a Dm - G hasn't got this. Therefore it isn't to be considered strong, but simply another progression. Aside from this, the writer purposely fixed us on G for the sake of the argument and more clear explanation without too many side-tracking. And they wrote this with the classical cadens, which was the point of the lesson. Which is why they used the IV - V - I, instead of the (in a minor key usually slightly more dissonant, and thus stronger ) jazz-cadens, the II - V - I.
    In ii-V-I the ii chord doesn't resolve to V chord. You always resolve to the I chord. If you end with the V chord, it leaves the progression unresolved. So the article is right. Of course Dm-G is common in ii-V-I progressions. But in this case the Dm doesn't resolve to G major. The Dm-G resolves to C major. C major is our tonic. While v-I progression is possible and it is used in many songs, it is definitely not as strong sounding as V-I. The article didn't say "don't use v-I progressions". It just said V-I sounds stronger.
    I know this type of stuff may seem boring to some guitarist but trust me if you intend to write your own music or even if you just want to learn cover songs it will help you to figure out the progressions.
    lesson on the I, IV, and V chords...and not a mention of the term cadence once. Bad lesson. If people want to learn about this stuff, do yourself a favour, ignore all this, and google cadence...you can learn enough from the wiki page, and learn a lot more as well. so many cadences, so little time also, this is not just popular in some genres, for almost all music, as the use of these three chords generally cement a keys full tonality. E.G. you can have shared chords in different keys, which open up other possibilities of tonality and key. However, in one progression if you were for example playing in C, and you played C, F, and G7, that would be in the key of C major, and C major only, so the use of these four chords are to set the key in full. cadences are great to learn guys, and really kick off with the inverted chords.
    Too bad you had to be disagreable with the author... I thought it was a very simple and easy approach. But thanks to you I went to see the term Cadence and did learn interesting stuff. So thanks to you both.
    I took a image of your work for a schoolar work about rock. Thaks by your aid!
    also, it is not BASED on maths...you can use maths to simplify things for yourself in regards to music, but it is not BASED on maths. That might not be much to you, but Music is the greatest art form humanity has ever created, its own 'language', its own 'rules', its own 'theory', which is not based on maths or anything other than vibrations that certain cultures across the world determine sounds better, or more correct.
    Music can indeed be based on mathematical relationships. Period.
    or rather...math concepts can be used to describe relationships in music...and in the physics of the universe. Nothing is based on Math, math is the quantification of naturally occurring relationships.