Pianist Ryan Ahern is ready for prime time.His concert, which was planned for more than a year and taped in February, will debut on KVIE Channel 6 at 8 p.m. Wednesday as part of the PBS station’s pledge drive.The Las Vegas-born Ahern, who splits his time between his hometown and Stockton, home of his fiance Mia Kinch, will be in KVIE’s Sacramento studio during the broadcast.