San Juan Singers director Angel Michaels promises “some of the most joyful and glorious music ever written” during the community chorus’s Whittier stage holiday concerts on Saturday and Sunday, December 19 and 20. This year’s featured work is English composer John Rutter’s song cycle built on the “Magnificat,” which Angel guarantees “will delight performers and audiences equally.” Yariv Aloni of the Victoria Chamber Orchestra will be the guest conductor, and he’s bringing along some orchestra members to play in the concert. Angel is very enthusiastic about the renowned Israeli-born conductor and violist: “He’s very personable and brings energy and passion to his conducting. He loves the music and loves musicians and he just pulls all that love out of his singers.”