The conventional cello recital has never been Matt Haimovitz’s cup of tea. Instead of programs devoted to standard repertory sonatas and transcriptions, accompanied by a pianist, Haimovitz has typically found ways to keep his concerts surprising, either by finding unusual repertory or assembling unexpected collaborations. In his current project, a tour with Voice, a British a cappella trio, he is doing both.

This curiously constituted quartet spent an eventful day in Portland on Friday, with Haimovitz giving a master class at the University of Southern Maine, and Voice braving the snow to give a pop-up concert at Whole Foods. In the evening, they reconvened for a delightfully inventive concert at the university’s Hannaford Hall, as part of the Portland Ovations series.

Both sides bring specialties to the collaboration. Voice, which was formed in 2006, has long been devoted to the music of the 12th-century abbess Hildegard of Bingen, whose work provided the structural elements of the program’s first half. They opened the program with a freewheeling arrangement of Hildegard’s “Caritas Habundat” in which each of the performers – Emily Burn, Victoria Couper and Clemmie Franks, as well as Haimovitz – recited lines of an English translation of the Latin text.

Voice had the stage to itself for a more straightforward account of Hildegard’s ecstatic “Favus Distillans,” a paean to St. Ursula, surrounded by two contemporary scores based on Hildegard’s work. Marcus Davidson’s “Musical Harmony” (2012) clothes a text by Hildegard (about the elevating power of singing) in shimmering, occasionally jazz-inflected modern harmonies. Stevie Wishart’s “O Choruscans Lux Stellarum” (2012) uses a melody of Hildegard’s as the basis of a richly harmonized contrapuntal piece. (The Hildegard works, and derivatives, are all included on Voice’s recent “Musical Harmony” recording.)

The trio also sang two striking pieces composed for it by Ayanna Witter-Johnson – “On Cricket, Sex and Housework,” in which the text, by Jean Breeze, was presented, one word at a time, as a round-robin among the three singers, and “Just in Case,” a more conventional setting of another Breeze poem.

Haimovitz’s solo moments focused mostly on Bach, whose six unaccompanied Suites he recently recorded. Instead of playing one of the Suites intact, though, he offered beautifully sculpted and unusually brisk accounts of the Preludes from the First and Fifth Suites, each paired with a newly commissioned companion piece.

Philip Glass’ Prelude for Suite No. 1 alluded to Bach and then moved into its own realm, which proved also to be a restlessly chromatic departure from the consonance and repetitiveness (melodic and rhythmic) of Glass’ classic style. David Sanford’s “Es War,” composed as an overture to the Suite No. 5, touches on Bach more cryptically, drawing less on the Suite’s musical themes than on its inherent drama as the basis of a troubled, often spiky rumination.

Shakespeare seemed to be a shared passion. Among the evening’s highlights were three very different settings of Shakespeare’s Sonnet 60, “Like as the Waves,” commissioned by Haimovitz (by way of a competition) in 2014, as a contribution to the heretofore nonexistent repertory for cello and three voices. Felipe Sousa’s “Like as the Waves” sounded more Glassian than the Glass Prelude. Diana Rosenblum’s version is an appealing, chordal gloss, and Božo Banovic’s version, “Sonnet 60 of William Shakespeare,” is a languid vocal setting with cello commentary between the lines.

As a curtain-raiser for the first of these commissions, Haimovitz worked considerable magic with two short movements from Ned Rorem’s compellingly melodic “After Reading Shakespeare” (1980). And as a postlude, Haimovitz and Voice performed three Shakespeare-era lute songs – the anonymous “Three Ravens” and “O Mistress Mine” and Morely’s “It Was a Lover and His Lass” – in lively, updated arrangements, the first by James Ottaway, the last two by Voice’s Couper.

Glass fans startled by the non-Glassian Prelude were given a make-good in the form of the sixth movement of the composer’s String Quartet No. 3 “Mishima.” Voice sang the work’s violin and viola lines, with Haimovitz playing the cello part, an arrangement that worked surprisingly well. The performers closed the program with an arrangement of Leonard Cohen’s “Who By Fire” by Luna Perl Woolf that was attractive and spirited, if lacking in the gravity of Cohen’s version. They offered a single encore, a lovely rendering of an antique Spanish wedding song.

The next concert in Portland Ovations’ classical series is a collaboration between Wu Man, a virtuosa on the pipa (a Chinese lute) and the Shanghai String Quartet on March 31 at Hannaford Hall.

Allan Kozinn is a former music critic and culture writer for The New York Times who lives in Portland. He can be contacted at:

[email protected]

Twitter: kozinn