> Can someone please define what "JACK" is?
It's a new "Variety Hits" format which mixes upbeat hits of various adult formats from the past four decades together (Rock, Pop, R&B, Dance, Alternative, etc...). The idea supposedly came from iPod's on "shuffle".
Most of the stations run this format jockless. Some use other male names as their moniker instead of "Jack", such as "Mike", "Bob", "Frank", "Ted", etc...