On July 1, 2004, at 8 a.m., the station began stunting with a mix of music and soundbites featuring the word "Jack." At Noon, the station flipped to Adult Hits as 100.3 Jack FM. The first song was "Where the Streets Have No Name" by U2. The Jack FM format had been successful in a number of Canadian cities. CBS began putting it on several of its FM stations around the U.S., including Los Angeles, New York City, Chicago and other markets.