Understanding the V-IV-I

Jimmy, a student on the site, needed some clarification on the V-IV-I. Here it is for you as well. Let's start from the top so that there's no confusion.

When we speak of theory on the site we use a C Major Diatonic Harmonica. This harmonica produces the notes: C D E F G A B C. For blues we commonly play in 2nd Position, so we play in the Key of G. The key of G uses the following notes for its construction: G A B C D E F# (F-sharp) G.

If playing by ourselves, we can play those G A B C D E F# G notes in any order, in any rhythm, we wish, to create what we feel sounds good.

When we play with other musicians we follow a form so that we're all on the same page. There are chordal instruments and melody instruments.

We are commonly the melody instrument, playing the G A B C D E F# G notes.

The chordal instruments make chords from the notes in the Key of G (the same scale: G A B C D E F# G). A chord is built in thirds. If I want to play a I (one) Chord, I start on the 1st note of the scale, G in this case, and build in 3rds. This gives me the notes of G B D. This three-note chord is the most common construction of a chord (we'll add more notes soon). The I Chord is the most important chord because it is the home chord... the place of rest.

The IV Chord (four chord) is also very common, and is constructed by starting on the 4th note (C) and is also constructed in 3rds... creating the chord C E G. The same principle is used for the V Chord, which is D F# A.

The 12 Bar Blues is road map if you will of where these chords are placed. The I Chord (the notes G B D) is played for 4 bars (also known as measures), this equals 16 beats. The IV Chord is then a departure for two bars (the notes C E G) and then resolves back to the I Chord for two bars (G B D). In blues we commonly think in four-bar lines or phrases, so we just played the first and second lines. We're now on the last (third line), the V-IV-I you're looking to understand better. The V Chord (D F# A) is for one bar, then the IV Chord (C E G) is one bar, and then the I Chord is for about a bar and a half (depending on how the turnaround is played) and the last couple of beats are the V Chord again to create what we know as the turnaround.

This is the 12 Bar Blues as we commonly know it (yes, it can change).

The laws of music require that we match with the other musicians. If I, the guitarist, am playing the note B and you, the harmonica player, are playing C, it will not sound good... we are not in "harmony" with each other.

So, here is the basics of melodic theory, as it pertains to a soloist...

On the I Chord (G B D), you will match if you play G B or D on your harmonica. This is holes 1, 2/3+, 3, 4 and 6+ for example. Okay... they play G B D... you play G B D... all is good. You are playing what are called non-actice notes... they match... they're pretty... you should mostly use these notes because they match. ONLY using these notes will sound boring.

If you also play the notes of the scale (G A B C D E F# G) it will bring some interest in. If you play G for example, and then use the note from the scale "A" to use as a passing tone to "B," a chord tone, this is the most common way to bring interest into a melody. The Chord Tones (G B D) are the most important, and if you hold on a note, it should be a chord tone... use the other note of the scale to move you around and create interest. You COULD, and we DO, HOLD notes of the scale outside of the chord... but be aware that they will be DISSONANT and will need to be resolved to a Chord Tone. These NON-CHORD TONES are known as ACTIVE TONES due to the fact that they are dissonant and actively seek to be resolved.

There is still one more level... the level that makes blues what it is... the OUTSIDE TONE. An Outside Tone is not of the chord (G B D in our example), and not of the scale of the chord (A C E F#... what we called "Active Tones")... they are OUTSIDE the scale... or outside what we commonly call the "Key" of the song, which in our example is the KEY OF G (the notes G A B C D E F# G). Some of these Outside Tones are the notes that make the Blues Scale. So, if G B D is the chord, and the notes of the scale other than those notes (A C E F#) are the active tones, then everything else are Outside Tones (G#/Ab, A#/Bb, C#/Db, D#/Eb and F). These notes AGGRESSIVELY seek to be resolved and should be used springy, like a strong spice... in the right moderation... and used in combination with the right ingredients... can be VERY exciting. If used in the wrong way, it can make your music sound awful. This is why in the first five years of our woodsheding years we copy, copy, copy... we're at the lower level of the mastery tree and don't know how to create great phrases, so we copy those that do.

Alright... let's recap...

I have now defined the scale you play (G A B C D E F# G) when playing your C Harmonica in 2nd Position. I have defined the three chord used in blues... the I Chord (G B D), IV Chord (C E G) and V Chord (D F# A). I have given you an example for the hierarchy of which notes should be played to match over a given chord for melodic purposes (the I Chord in this example) and the notes that can be played to ad interest (Active Tones and Outside Tones). Let me stress before we move on that you're in the beginning stages of improvising, so you want to focus on Chord Tones (G B D for the I Chord), they have the highest probability of matching, and you want "safe" at this stage in the game.

Okay, now for the V-IV-I

The V (D F# A), IV (C E G) I (G B D) chord progression, is ONLY found in ONE place within the 12 Bar Blues Progression... bars 9, 10 and resolving on bar 11. Simply stated, the more you use of the chord tones, the cooler you sound. The more advanced the player, the mote they use of the chord. So, for the V Chord you're playing a lot of (but not exclusively) D F# and A notes. For the IV Chord you're playing a lot of (but not exclusively) C E and G notes. For the I Chord we commonly play one note, that's it... the root note of the I Chord, G (2/3+ 6+ 9+). The job of bar 11 is to resolve what's been played in bars 9 and 10. After the downbeat of bar 11 we're in Turnaround territory.

When I hear a cool V-IV-I lick... for example... the V-IV-I lick from "Gary's Blues" in the 4th Chorus is super-cool. I can learn it and use it whenever the V-IV-I (again, bars 9, 10 and 11 within the 12 Bar Blues) comes around when playing to the 12 Bar Blues (jam track or band). Don't read into this any further... they played a cool lick over bars 9, 10 and 11... I can steel that lick and use it any time... or every time if I wish... bars 9, 10 and 11 come around when soloing.