Who was the first rock act to apply Jamaican music?

That may be true for their first two albums, but they jumped on the bandwagon of British punk rockers like the Clash who had done it before.

Yes, but he went to NYC right out of high school and was probably exposed to Jamaican music there. Along with Kingston and London, NYC was the place where the proto-reggaes were developed. And it’s not like calypso was foreign to American ears.

If for some strange reason you didn’t count The Specials, or The Selecter, or Madness, or The Beat, or indeed any of the other Two-Tone bands. Actually, Bad Manners were probably the first of them.