There's a short paragraph in Ed Ward's "Italo-American Rock," an excellent essay that I first encountered in the original edition of The Rolling Stone Illustrated History of Rock & Roll, that encapsulates many of the key points I want to make about this thing called East Coast Horn Rock:
In 1964, in the white urban ghettos of New York, New Jersey and Philadelphia, while the rest of the world was getting into the Beatles, a bunch of oldies collectors and nostalgics staunchly clung to the old sounds. In northern New Jersey, a full-fledged acapella revival took place. A lot of young Italian kids got into it, and a lot of Puerto Rican kids, too. Ward is referring to doo-wop, which thrived in New York in the 1950s. But the sense of nostalgia he mentions can be expanded to cover a lot more ground. As a kid who grew up in an Italian American neighborhood in central New York, I noticed our oldies stations sounded significantly different from those in southwestern Michigan, where I spent long summer vacations with my grandparents. In addition to doo-wop, the East Coast DJs enjoyed spinning supper-club schmaltz, Tin Pan Alley pop, Broadway show tunes and, yes, just way more horns and brass in general. Dion, Frankie Valli & The Four Seasons and The (Young) Rascals were kings, not the Fabs, The Stones and other British imports.
If rock 'n' roll has a regional identity on the East Coast, from Boston down to Philly, then it's this nexus of styles and genres, all of which are heavy on crooned vocals and sentimental ballads soaked in horns. Throughout the 1970s and early '80s, the sound manifested itself in a wide array of divergent artists, from Billy Joel and Bruce Springsteen (the "Jersey Shore Sound") to David Johansen and Lou Reed. Even a group as avant garde as Suicide can be said to belong to this tradition in certain key respects. A track like the classic "Dream Baby Dream" with synthesizers replacing doo-wop voices, which were themselves standing in for horns back in the day is really nothing more than an update of vintage Dion pop. After all, Martin Rev and Alan Vega were just two Jewish American kids who grew up in Brooklyn, listening to all the same radio stations as squares like Joel.