I am in love with this song today. It is melodically interesting – surprising, even! It is lyrically perfect, and with or without instrumentation (the version linked here is acoustic), it conveys so much depth through the chord progressions and melody.
The surprise in the melody occurs at 1:15, during the line “I could stay forever if I tried”. What you have going on musically is a chord progression in the intro and verses that goes like this:
CM/GM/Am/Em (C major, G major, A minor, E minor)
and then in the chorus, the chord progression turns into this:
GM/DM/C6/CM (G major, D major, C 6, C major)
GM/DM7/Am/CM (G major, D major 7, A minor, C major)
In the first half of the chorus, the C6 chord is voiced in an inversion, so that the “A” is on the bottom, so it’s actually very similar to the second half of the chorus, there’s just an added note (“G”). In the second half of the chorus, the D major 7 means the 7th scale degree is included in the D major chord, so it’s D,F#,A,C. For a really cool chord-building tool, check out this awesome website.
The cool part comes in the second half of the chorus – with the DM7 chord (forever if I tried). The word “tried” is the 7th of the chord (the “C”). So, in the first half of the chorus, the melody goes something like this:
I’ve been waiting here (C-C -CB- B) all night (CBA- A)
If you’re not gonna show (C-C-B-AG-G) we’re not gonna fight (B-A-AG-G)
I could stay (C-B-B) forever if I tried (BCB-A-B-C)
Surrounded by the things (ABA-A-G-G) like a shadow in the light (G-G-BA-AG-G)
Sorry if that’s confusing, but basically each syllable gets a note inside the parenthesis. Too bad I can’t post sheet music!!