I feel as though the most significant difference between composition of contemporary pop and oldies is form. Contemporary pop music (whoever is currently on the radio) is typically verse-chorus form, while "oldies" such as Elvis, Buddy Holly, and early 60's garage rock, are strophic in form or are simply standards (12 bar blues, for example).
My question: Are there other distinguishing stylistic characteristics for these two groups? I am wondering if the drums (swing drumming?), tone (of the guitars for example), rhythm/voicing of guitars (you don't see Buddy Holly ripping through eighth-note power chord sections) lyrical content (different themes?), vocal delivery, etc . . . play a significant role in making something feel "classic" or "nostalgic". If you wanted to write an early-rock hit, what would be some items on your check list?