Rascal Flatts will expand their sound when they join conductor Keith Lockhart and the Boston Pops Esplanade Orchestra on the Boston Pops Fireworks Spectacular, a TV special airing July 4 on CBS. Rascal Flatts will perform several of their hits with the orchestra during the live telecast from the Charles River Esplanade in Boston. The special will be hosted by Craig Ferguson, the Scottish-born late night talk show host who became a U.S. citizen earlier this year. … In related news, Jerry Lee Lewis, Huey Lewis & the News and American Idol winner Taylor Hicks are among those performing on the PBS special, A Capitol Fourth. Actor Jimmy Smits will host the program live from the U.S. Capitol in Washington, D.C. The July 4 telecast will also feature Broadway star Brian Stokes Mitchell, classical vocalists Hayley Westenra and Harolyn Blackwell and the National Symphony Orchestra.