Dancers perform around the Tree of Life with the Tabernacle Choir at Temple Square and Orchestra at Temple Square during a Christmas concert at the Conference Center in Salt Lake City on Thursday. Earlier in the day, actress Kelli O’Hara said she never imagined she would one day perform in front of the Tabernacle Choir at Temple Square. “This is the ultimate invitation, isn’t it?” she asked during a press conference with fellow actor Richard Thomas, known for playing John-Boy on “The Waltons” TV drama. The two will perform as the guest artists at the choir’s 20th Christmas concert through Saturday at the Conference Center. Audiences at this year’s concerts can expect to hear old Christmas favorites as well as some music they probably haven’t heard before, including one piece that is particularly meaningful to O’Hara, according to Mack Wilberg, music director of the Tabernacle Choir and Orchestra at Temple Square. Although all tickets to the concerts have been distributed, standby seating may be available. See stories on Pages C1 and 6.