tldr: Creep is in G major and consists of four chords, G – B – C – Cm. The G and C chords are the I and IV of G major, but B and Cm are foreign to the key. Their use here— borrowed from G major’s relative and parallel minor keys— adds a D# note between the D note of the B chord and E note of the C chord. This creates a voice-leading pattern of D – D# – E – D# that repeats throughout the song. Although there isn’t a lot of lead guitar work besides the cool octave solo, this is a great song to practice changing scales over the chord changes, and I go into some options below.
Creep Full Analysis
I was playing around with Creep and figured I’d post a quick breakdown on the song, which has some interesting twists based on borrowed chords.
The key is G major and the chords are simply G, B, C, and Cm. The G and C are the diatonic I and IV, but the unexpected chords that give the song its unique feel are B and Cm, as neither comes from the G major scale. The diatonic versions of those chords would have been Bm and C major. The difference is that B and Cm have an D#/Eb as their third note (which is not in the key of G) instead of D and E, respectively.
The consequence of this difference is a voice-leading pattern that repeats throughout the song (in bold):
G: G B D B: B D# F# C: C E G Cm: C D# G
So, D – D# – E – D# – D – D# – E – D# and on and on throughout the song.
The B and Cm chords fit more broadly within the G major key as borrowed chords. The most common places to borrow from are the relative minor key (here E minor) or the parallel minor (here G minor), and both are used here: the B chord is taken from E minor, and the Cm is taken from G minor.
Now, a relative minor key by default has all the same notes as its relative major, so you might think that it wouldn’t make a difference to borrow from it. The trick is that you don’t have to use the natural minor; you can also use the harmonic minor (which has a raised 7 note relative to the natural minor) or melodic minor (raised 6 and 7). The V chord of E harmonic minor is B instead of Bm because of that raised 7th note, which is the D# note.
Also note that a V chord has special significance in harmony, as it has a natural tendency to pull the ear toward its I chord. Instead of a borrowed chord, the B chord could be classified as a “secondary dominant” V/vi chord, meaning that it is a dominant from another key, E minor, that creates an expectation that it will resolve to the i chord of that key, Em, which is the vi chord of the key we are in, G major. You can hear this in action by actually playing an Em chord after the B; it sounds pretty good. And even though that isn’t what happens in this song, which moves to a C chord, that could simply be characterized as a “deceptive resolution” of the secondary dominant to a chord that is not its I chord.
It’s subjective, and your opinion may reasonably differ, but my take is that the B chord doesn’t primarily serve that role here. Because of the context of its role in the voice-leading pattern discussed above, I view it instead as a borrowed chord.
The solo in the song, which is done using octaves, primarily follows the chord tones of the progression. If you don’t know how to play an octave, the first one, G, is played by holding down the G note at the 10th fret of the A strong and the G note at the 12th fret of G string while gently muting the string in between with the bottom of your index finger (the one holding down the lower G note). The octaves, and the chords over which you play them, are:
Chord Octave(s) Frets G G 10 B D#, F# 6, 9 C E, G 7, 10 Cm D#, C 6, 15 G B, G 14, 10 B F#, A 9, 12 C G, E 10, 7 Cm D#, C 6, 3
Notice the notes that are used: all are within G major except for that borrowed D# note played over the B and Cm chords.
Although there isn’t much lead improvisation in the song itself, you can actually do a lot with these chords. Although there are many options, I’ll highlight just a few:
G: G major *or* G phrygian dominant *or* G mixolydian B: B major C: C major *or* G major Cm: C harmonic minor
Although I list 6 scales, there are actually only 3 scales at play other than G major: G phrygian dominant is identical to C harmonic minor, and G mixolydian is identical to C major. Why name them differently? Generally it has to do with the tonic of the key, but here I’m focusing on their relationship with the chord over which they will be played.
Playing G major, B major, and C major scales over the G, B, and C chords, respectively, is self-explanatory. C harmonic minor over the Cm chord works even better than C natural minor because it replaces a Bb note with a B note. That note is in the G and B chords, and the C major scale of the C chord also has B, so it just makes the C minor scale sound a little more consistent with the song. And playing C harmonic minor over the G chord— G phrygian dominant— carries that exotic feel into the G chord while containing all of the notes of the G chord. Playing G mixolydian over the G chord does something similar, but less exotic and drawing from the C chord instead of Cm.
If you go with G phrygian dominant over G, try also adding an F#, which works because it is in G major. This creates an 8-note scale known as the phrygian dominant beebop scale, which is more commonly used in jazz.
These aren’t the only options, of course. For example, you can play the parent scales for the borrowed chords (E harmonic minor over the B chord, G minor over Cm).