1. CHART BEAT

    April 21, 2005 12:00 AM EDT Fred Bronson reports on chart activities relating to Mariah Carey, Secret Garden, "American Idol"/Queen and 50 Cent and B5. EMANCIPATED: For the first time in seven-and-a-half years, Mariah Carey is sitting in pole position on The Billboard 200. "The Emancipation of Mimi"…