"(Theme from) The Monkees"

I was thinking about "(Theme from) The Monkees" yester-day, specifically the bass part during the first verse, which is something like:

For most of this, the bass alternates between the root and the fifth of the chords (A minor | F major | D major | G major).  Musically, this gives something of an impression of footsteps, and this matches the "walkin'" that's in the lyrics:  "Here we come / Walkin' down the street."