Scores of the valley's shower singers tuned up their voices Sunday, ringing in the holiday season with choruses of "For Unto Us a Child is Born" and "Hallelujah." The Utah Chamber Orchestra and Utah Symphony Chorus provided the framework for Handel's beloved masterpiece, while music lovers in the Symphony Hall audience joined in during the 13th annual Messiah Sing-In, sponsored by the Deseret News and Utah Symphony Chorus. The performance was anchored by soloists Carol Nelson, soprano; Carla Cook, mezzo-soprano; Michael Ballam, tenor; and Steven Meredith, baritone.