There were two, mainly.
I grew up 15 miles west of NYC in Northern NJ.
My Mom would always listen to Ted Brown & The Redhead, 6AM-10AM weekdays, on 1050 WMGM NYC, and the kids, like myself would be listening to 1050 WMGM (they played RnR) and 1010 WINS (NYC's first RnR station in Sept.,1954).
This was around the mid-50's.
Also, at that time my cousin, she would listen to 1430 WNJR Newark/NYC. So I got into it too.
They were R&B that my cousin was into, Doo-Wop, etc. Plus they had a large white listening audience for an R&B station back then.
WMCA 570 NYC came around in 1958 or so with RnR, then in late 1960, 770 WABC went fulltime RnR. 1050 WMGM changed format to MOR and calls back to WHN in 1962 . . . 1010 WINS went All-News in 1965.
WABC was beating them big time.
570 WMCA hung in there, finally giving up on RnR in the early 70's.
Additional note . . . kids in their cars all had the last button set for 1520 WKBW in Buffalo,NY, they went RnR I think in 1958 and came in loud at night in the NYC area.
During the day in Northern NJ the 1520 spot was quiet unless you had a good radio and you'd hear the 1520 daytimer out on Long Island, weak but there.
Al