Okay. Latest song…uses the four-chord trick first most recognisable as Pachalbel’s Canon in D and then the Axis of Awesome but in the relative minor key. The chord progression in my chorus follows the vi-IV-I-V (Bm-G-D-A, the Canon would be D-A-Bm-G; I also use a variation in the third line of the chorus, suspending it on A/Asus4 instead of resolving to add tension. The progression for the intro and the verses is slightly different V-IV-iii-ii, which comes out as D-G-F#m-Em, a descending, moody progression, which hopefully sets the scene for the song and itself a variation on the original Canon sequence in some sense.
Incidentally, I’m not the first person to re-use the four-chord trick (obviously), as you may be aware Axis of Awesome has covered the major key original in their medleys of Journey, James Blunt, U2 etc. My sequence is the relative minor variation sometimes referred to as “the sensitive-female chord progression” and used by Aimee Mann (“Borrowing Time”), Secondhand Serenade (“Fall for You”), Katy Perry (“Fingerprints”), Moby (“Every Day It’s 1989”), Sugarland (“Take Me As I Am”), Carolina Liar (“I’m Not Over”), T.I. (“Whatever You Like”), Natasha Bedingfield (“Angel”), Guns ‘n Roses (“Shackler’s Revenge”), Beyoncé (“If I Were a Boy”), Joan Osborne (“What if God was one of us?”), Sarah McLachlan (“Building a Mystery”), Boston (“Peace of Mind”), Iggy Pop “(The Passenger”)…