One of the characteristics of the 60s radio playlists was the bizarre variety of genres reflected in the songs that you could hear on one station at any given point in time. You might have Latino stuff like Sergio Mendes & Brasil '66 or Herb Alpert & the Tijuana Brass mixed in with the British Invasion, surfing music and Englebert Humperdinck or Tom Jones. And of course, soul music was everywhere.
So having a song like Cara Mia in the Top 10 for 11 weeks in the summer of '65 wasn't that weird, even though its doo wop vocal style harks back more to the time when it was first recorded, in the 1950s, than it does to the 60s.
Very few songs send chills up my spine the second I hear them, but Jay Black's incomparable rendering of this never fails to cut right to the quick. He was one of a few artists of that time (Roy Orbison and Gene Pitney being two others) whose mastery of his powerful voice and high vocal range could - and still does - bring tears to the eyes. It's a cliche, but it's true here: they don't make songs like this any more.
(Interesting factoid that I didn't know until now - before they became Steely Dan, Donald Fagen and Walter Becker were part of Jay and the Americans' touring band in the late 60s.)