In this installment of How Does This Song Work?, you take a look at the song “Thank You” by Led Zeppelin. You get to know the music theory behind the song, including the key, why the chords work together, and which scales to use for soloing.
“Thank You” Introduction Chords
The song begins with a 12-string guitar playing the chord changes D-Cadd9-G/B-D. To make things more interesting, guitarist Jimmy Page repeats a melodic figuration in the upper voice using the note D along with the notes G, F#, and E. These notes create the sound of Dsus4 and Dsus2 when played over the D chord. Adding the 4th and 2nd like this is a very common way to embellish an open-position D chord. Jimmy Page takes the idea farther by repeating the figuration over the C and G chords too.
When you think of the chords in their most basic form, they are D-C-G-D. These chords are 5-4-1-5 out of the G major scale. You can write it in Roman Numerals as V-IV-I-V. Because the G scale’s 5th degree, D, is functioning as the tonic (the tonal center of the music), this chord progression is in a mode. The fifth mode is called Mixolydian, so the music is said to be in D Mixolydian mode.
In music, you count the tonic pitch as “1.” You think of other pitches in relation to the 1. In the introduction to “Thank You,” if your primary chord, D, is “1,” then the C chord is “♭7” and the G chord is “4.” When the chord progression is numbered to reflect the D center, the chord progression is 1-♭7-4-1. You can write it in Roman Numerals as I-♭VII-IV-I.
Even though the beginning of “Thank You” uses notes and chords out of the G major scale, you think of the music as being in the key of D since the primary pitch is D. The music is notated using a key signature for D major. Accidentals are used to change the D key’s C# notes to C natural notes.
“Thank You” Verse Chords
The verse in “Thank You” is based on the same basic chord changes as the introduction. You get introduced to new chord changes in the song’s pre-chorus that begins at 52 seconds.
“Thank You” Pre-Chorus Chords
I call the section of the song at 52 seconds that begins with the lyrics “Kind woman I give you my all” the pre-chorus. The first chord in the pre-chorus is Bm. D and Bm are relative major and minor chords. Shifting between the relative major and minor is a very typical movement in music. This song section is made more interesting by the E major chord that follows the B minor chord. Usually, the E chord is minor in the key of B minor.
I think of the E major chord as a secondary dominant leading to the A chord you play a few measures later. The A chord is the V of D. The A chord sets you up to return to the D tonic and resume the verse chord progression. In all, I think of the pre-chorus chords as a lengthened version of vi-II-V-I (6-2-5-1). I also hear the Bm-E chord changes as some temporary B Dorian mode out of the A major scale.
The end goal of the pre-chorus chords is to bring you back to D, but you don’t make it back to D just yet. After finishing the pre-chorus on the A chord, the music takes a surprise turn by going to C in the chorus, which I discuss next.
“Thank You” Chorus Chords
The next section of the song is what I call the chorus. This section begins at 1:05 with the lyrics, “Little drops of rain.” The chord changes here are C-G/B-D. These chords are similar to the verse but start on the C chord. The C chord adds an element of surprise because your ear was expecting a return to D.
You get the return to D you expect when the pre-chorus chord changes, Bm-E-A, get replayed at the end of the chorus, and the music finally returns to D at 1:41. You resume playing the intro/verse chord changes at this point.
“Thank You” Guitar Solo Scales
The guitar solo to “Thank You” begins at 1:52 and is played over the intro/verse chord changes D-C-G-D. Jimmy Page plays the solo on an acoustic guitar and makes use of notes from the D major scale. What’s interesting about Page’s scale choice is his ignoring of the D Mixolydian mode. The D major scale has a C# note in it. The C# note would generally clash with the C natural note in the C chord. But in this case, the C# notes are imperceptible because Page gives no particular emphasis to them.
If you want to tie your lead lines more closely to the chord changes during the solo, play D Mixolydian mode scale patterns instead of D major scale patterns. D Mixolydian mode scale patterns are the same as G major scale patterns, and they contain C natural. Another option is to play D major scale patterns but change the C# to C natural during the C chord.