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We have already seen how the V-I change gives a feeling of resolution, or completion. We will now see how composers have exploited that feeling, and extended it.
If we start a piece of music on the chord G7, we might expect it to resolve to C major. Suppose we add a flattened seventh note to that C chord, making C7, and treat that as the dominant of another key: we could then resolve from C7 to F, making a V-I progression in F major. We could then add an Eb to the F major chord, making F7, which would resolve to Bb. If we keep doing this, we will go through the pattern G-C-F-Bb-Eb-Ab-C#-F#-B-E-A-D-G. Notice that we have gone through all twelve keys, ending back where we started. A movement from the V chord to the I chord can be thought of as a movement of either a perfect fifth downwards, or a perfect fourth upwards, so this sequence is known as the cycle of fourths or the cycle of fifths. This pattern of resolution following resolution has been used by many songwriters and composers. Autumn Leaves, All the Things You Are, Parisian Walkways, The Adams Family theme, and A Windmill in Old Amsterdam are commonly known songs using the cycle of fifths. Let's look more closely at one of those songs.
E A
They're creepy and they're cooky,
D G
Mysterious and spooky
C F
They're altogether ooky,
B E
The Adams family.
Listen to this part of the song. The chords follow the cycle of fifths, starting from E: EADGCF but then they jump to B, which resolves back to E. If the writer had carried on going round the cycle of fifths, the next chord would have been Bb. Songs written using the cycle of fifths do not usually go all the way through all twelve keys, but jump out at some point in order to resolve to the tonic key by a more direct route. Now we'll look at something interesting that happens when we use dominant seventh chords in the cycle of fifths. We'll simplify matters by omitting the fifth in each chord, since this note remains the same for major, minor, and dominant chords, and so does not contribute to the character of the chord as the third and seventh notes do. Starting at C7, the cycle of fifths goes through these chords (written root, third, flat seventh): C E Bb Now look at what happens if you go through the sequence going from the third of one chord to the flattened seventh of the next, then the third of the next chord, etc. Starting from the third of C7, which is E, then the flattened seventh of F7, which is Eb, and so on, we get the sequence E, Eb, D, Db, C, B, A#, A, G#, G, F#, F. This sequence of notes is a chromatic scale - it goes through all the notes one semitone at a time. If we started on the flat seventh of C7, via the third of F7, we would get the chromatic scale beginning Bb, A, Ab, G, etc. We can make this chromatic movement even more obvious by dropping the seventh note of alternate chords in the sequence (that is, the chords F7, Eb7, C#7, etc.) by one octave. This gives us: C E Bb (R-3-b7) If we play this on the piano, with the root in the left hand, the right hand would play a series of chords which descended by a semitone each time. Notice that in these right hand chords, the roles of the higher and lower notes swap between third and flat seventh each time the chord changes. For guitarists, here is tablature for the same sequence: E |-------------------|------------------|----------------|--------| B |-------------------|------------------|----------------|--------| G |15---14---13---12--|11---10---9---8---|7---6---5---4---|3-------| D |14---13---12---11--|10----9---8---7---|6---5---4---3---|2-------| A |15--------13-------|11--------9-------|7-------5-------|3-------| E |-----13--------11--|------9-------7---|----5-------3---|--------| See how those thirds and sevenths intertwine to make the descending chromatic scales? Let's step back into diatonic territory now - remember, diatonic means just using the notes from one scale. If we are playing in the key of C major, we are likely to resolve a phrase or song on a C major chord. The strongest resolution we can make to that C chord is from G7, giving us the V7-I chord sequence, also known as the perfect cadence. If we want to extend this by resolving from something to the G7, the obvious choice from the cycle of fifths would be a D7 chord, but this is not diatonic to C major - so instead we would use D minor or Dm7. Listen to the change Dm7-C . This ii-V sequence is not quite such a strong resolution as V7-I, but there is still a definite "pull". Putting these together gives us the sequence ii-V7-I which is a very commonly used chord sequence in jazz and popular songs. Think of "I get a kick out of you", or the words "Christmases be white" from "White Christmas" amongst countless others. |