Country star Darius Rucker will headline Naples’ sixth-annual Live Fest this December. The outdoor show is part of the Grant Thornton Invitational, a mixed-team golf event featuring PGA and LPGA pros. Rucker, a Grammy Award winner with four No. 1 albums in the Billboard country chart, will be joined by Southwest Florida band Rock Republic and “American Idol” semifinalist Casey Bishop. Tickets for the concert go on sale June 27, with general-admission tickets priced at $150. VIP tickets and other packages are also available.