“Pure luck” is how conductor Michael Waldron describes his discovery of Variations on a Hymn by Orlando Gibbons, a piece by the English composer Lennox Berkeley that had languished virtually unnoticed since premiering at the Aldeburgh Festival in 1952. “I was in a music shop and found a vocal score for it,” Waldron tells Apple Music. “I did some research and found it had never been recorded before.” Variations forms the centerpiece of Colourise, Waldron’s new album with the London Choral Sinfonia, where he is music director. Lasting 18 minutes, Variations is scored for choir, organ, and strings. “And there’s a beautiful middle verse, which is just for the tenor solo,” Waldron adds. Andrew Staples is the resonant soloist on this first recording. The other pieces on the album look more familiar, but also contain surprises. Vaughan Williams’ 5 Mystical Songs is performed not in the usual version with large orchestra, but in the composer’s own arrangement for strings and piano. “It allows a lot more for the intimacy and immediacy of the text,” Waldron says. “And our baritone, Roderick Williams, is second to none for this sort of repertoire.” Vaughan Williams’ popular The Lark Ascending is also, Waldron says, “seen through a fresh lens.” Normally, an orchestra supports the soaring solo violin, but in Colourise, the voices of the London Choral Sinfonia provide a glowing accompaniment. “And that,” explains Waldron, “is the whole point of the album: to take something that’s old and in black and white and shine a new light on it.”