A recent invitation from the Mormon Tabernacle Choir to join a virtual “Hallelujah” chorus resulted in hundreds of YouTube entries of singing fans and groups. The final product, which features a virtual grid of uploaded fan videos singing above the Mormon Tabernacle Choir, YouTube musicians Peter and Evynne Hollens, and scores of in-person volunteer voices, created the largest and first-of-its-kind virtual “Hallelujah” chorus video.