Following the contrastingly animated We Need a Little Christmas by a year, the a cappella group's generally warm and tender fifth seasonal album, Evergreen, sees Pentatonix cover 13 varied selections alongside one original, an acoustic guitar-accompanied title track that pays tribute to mothers. Among the more traditional entries here are "I Saw Three Ships" and a risk-taking, melody-altering "Over the River," which features violinist Lindsey Stirling. Another noteworthy guest, Alessia Cara, appears on a sweet, straightforward version of "Frosty the Snowman." Other songs from the jazz and vocal eras include "Home for the Holidays" and a version of Jule Styne and Sammy Cahn's "It's Been a Long, Long Time." Elsewhere, rock era representatives include Paul McCartney's perky "Wonderful Christmastime" and Joni Mitchell's heartbroken "River" as well as more-surprising inclusions like the affection-themed, non-holiday songs "I Just Called to Say I Love You" and "My Heart with You," a loyal, rhythm section-free cover of the 2008 Rescues tune. The set closes with a truly a cappella edition of "We Wish You a Merry Christmas" that sets the tone for caroling.