The Tanglewood Festival Chorus usually performs with the full BSO, but once a year it gets to present an a capella concert drawn from centuries of choral music, sacred and secular. The Tanglewood Prelude Concert on Friday the 23^rd was such case.

Music director James Burton suggested a program that would continue the summer’s emphasis on the life, and especially the commissions, of Serge Koussevitzky in the year of his 150^th birthday. To be sure, almost all of Koussevitzky’s commissions were for orchestra works or the rare opera. But the Koussevitzky Music Foundation continues that extraordinary activity up to the present day. Many of the composers he commissioned also wrote for a capella chorus. Ten of those short works made for a varied and interesting program.

The ‘earlier’ composers in the program (Stravinsky, Messiaen, Britten) are figures that Koussevitzy personally commissioned. The selections here are interestingly different from the commissioned works and the scores we know best today. Most strikingly, Stravinsky’s Ave Maria and Messiaen’s O sacrum convivium are works for calm liturgical use, avoiding the striking rhythms and varied colors of the Symphony of Psalms or Turangalîla. Britten’s Hymn to the Virgin is very early in his output, composed when he was 16 and revised at the ripe old age of 20. Its anonymous early 14^th-century sources alternate rhymes in English with rhyming lines in Latin. Burton apologized to the audience for including this Christmas piece and several others in an August program, but he noted that the TFC will not get a chance to sing a delicate a cappella work like Britten’s in its December Pops performances.

Francis Poulenc’s Salve Regina is immediately identifiable as a work in that composer’s mystical religious style that appeared in about half of the movements of his BSO commission Gloria, commissioned by the Koussevitzky Music Foundation (KMF) after the conductor’s death (and premiered at the BSO under the direction of Charles Munch.

William Walton received a KMF commission for his one-act comic opera The Bear (after a Chekhov farce), filled with delicious humorous quotations from famous compositions. The text for his a cappella piece, Set me as a seal upon thy heart, drawing texts from the Song of Solomon, was composed for a friend’s wedding.

Michael Tippett spent a lot of time in his early years leading orchestras and choral ensembles of working men and women, including the study of early music, including madrigals. His piece here—one of a group composed by ten British composers to celebrate the coronation of Queen Elizabeth II—evokes the part-writing texture of the Renaissance form in setting a modern text by Christopher Fry that also evokes 16^th-century poetry. The music was rather dense, and, coming at the beginning of the program, it struck me that the singers were feeling slightly overwhelmed, though that was not the case with the rest of the program.

Another score intended for the Christmas season was Helen Grime’s Telling, adapted from a 16^th-century text that the composer apparently found in a modern setting by Michael Finnissy, but she liked the words and set it herself in a simple three stanzas plus refrain. Grime is an English composer, but she was a Tanglewood composition fellow in 2008 and has been commissioned twice by the Boston Symphony.

George Walker was the first African American to win the Pulitzer Prize in composition, for his BSO commission Lilacs. He has also received two KMF commissions. The piece performed here was Stars, written for his sister, who was, like him, a distinguished pianist; she became the first tenured female African American professor at Oberlin College.

Augusta Read Thomas studied with (among many others) Oliver Knussen at Tanglewood in 1989 and has returned here frequently, including as curator of the Festival of Contemporary Music. She and her husband Bernard Rands were represented on a unique Symphony Hall program when Mstislav Rostropovich turned 70; they both premiered cello concertos written for him, the first time a married couple had both taken part as composers having world premieres together. In 2019. She has been commissioned by the BSO for her Cello Concerto No. 3 and Helios Chorus II. Andris Nelsons led the Boston Symphony in the premiere of Magic Box to celebrate the creation of the Tanglewood Learning Institute in the Linde Center. The TFC performed The Reawaking, a gentle, harmonically sweet setting of a William Carlos Williams poem that offers a poetic description of a spring dawn.

The closer was most surprising considering how James Burton felt the necessity of explaining it to the audience. Most choral singers are not prepared to respond to a musical instruction on the lines of “sing whenever you like,” but that was the essence of the central part of Jonathon Harvey’s Come, Holy Ghost, an anthem for Pentecost. The text adapts the Latin poem “Veni Creator Spiritus” in an English version by Bishop J. Cousin. The description of Pentecost in Acts 2: “…there came from the sky a noise like that of a strong-driving wind, which filled the whole house where they were sitting.” Harvey’s work calls for a large choir to divide into many sections, and at the climax of the work, the voices perform aleatorically—overlapping in multiple ways, whenever they like. This creates an uncannily realistic sound of a rushing wind. Eventually it dies away as the voices come together again for the liturgical close. When the piece was new, in 1984, it was regarded as ultra-modern. But the lady sitting next to me said, “I really liked that.” A sentiment with which I thoroughly agreed.

Steven Ledbetter is a freelance writer and lecturer on music. He got his BA from Pomona College and PhD from NYU in Musicology. He taught at Dartmouth College in the 1970s, then became program annotator at the Boston Symphony Orchestra from 1979 to 1997.