Open the Door for Three, a trio of Irish musicians whose penchant for scholarship complements their talents for arrangement and performance, will be a featured act in the 13th annual “A St. Patrick’s Day Celtic Sojourn” production, which takes place March 15-17 with shows at The Cabot Theatre in Beverly, the Zeiterion Performing Arts Center in New Bedford, and Sanders Theatre at Harvard University.

Also in this year’s line-up is Brenda Castles, a concertina player from County Meath; Scottish harpist/keyboardist/vocalist Maeve Gilchrist; and vocalist/guitarist Keith Murphy, who serves as music director for the show.

WGBH-FM broadcaster Brian O’Donovan is the creator, producer, and host of “A St. Patrick’s Day Celtic Sojourn,” which follows the spirit and format of his long-running radio show, as does his annual “A Christmas Celtic Sojourn” production in December.

Open the Door for Three comprises Maine-based spouses Kieran O’Hare (uilleann pipes, flute, whistle) and Liz Knowles (fiddle) and Dublin-born Pat Broaders (bouzouki, vocals), now a Chicago resident, all of whom have extensive experience in the music scene. Knowles, for example, has played in “Riverdance” and as a member of Cherish the Ladies and the String Sisters, while also working in more contemporary circles with Tim O’Brien, Paul Cole, and Don Henley, among others. O’Hare has performed, toured, or recorded with Mick Moloney and The Greenfields of America and fiddlers Liz Carroll and Jerry Holland, as well as baroque performers Ensemble Galilei and singer-songwriter Bonnie Raitt. In addition to his long-time stint as a member of bohola, Broaders’s collaborations include Dennis Cahill, Liz Carroll, Martin Hayes, John Doyle, Paddy O’Brien, Robbie O’Connell, and Danú.

The three are also known for their diligent research, digging into books, collections, recordings, and other sources, and for the harmonies and well-crafted arrangements that typify their sound. They have recorded three albums, including the recently released “The Joyful Hours.”

Castles grew up in a musical family, and earned All-Ireland Fleadh titles in solo and group competitions. She learned tin whistle and concertina from Rena Crotty Traynor, and later with Mícheál Ó’Raghallaigh, one of the most respected concertina players today. She has recorded a solo album, “Indeedin You Needn’t Bother,” which includes her own compositions as well as tunes from distinguished musician/composers like Ed Reavy, Vincent Broderick, and Charlie Lennon.

Gilchrist, a onetime Boston resident who studied at the Berklee College of Music, has fashioned a unique approach to Celtic harp that draws upon contemporary influences, incorporating bits of jazz and world music. She has appeared regularly in the Boston area, including as part of “A Christmas Celtic Sojourn,” for which she is now assistant music director.

Murphy, who grew up in Newfoundland, also is familiar to Boston-area audiences through not only “St. Patrick’s Day Celtic Sojourn” but as a member of the Childsplay ensemble, and as a frequent accompanist for local Scottish fiddler Hanneke Cassel.  He has also played with prominent Irish performers like fiddler Liz Carroll and vocalist Karan Casey, among others. For nearly two decades, Murphy was part of Nightingale, the groundbreaking trio he founded with his fiddle-playing wife, Becky Tracy, and accordionist/pianist Jeremiah McLane. Besides his prowess on guitar, Murphy is widely praised for his cogent, expressive singing, in both English and French; he’s just released his second solo album, “Land of Fish and Seals.”

Other performers have yet to be confirmed, and updates and details about the show are available at wgbh.org/celtic.