Having marked their 20th anniversary this past year in grand style – with the release of the crowd-funded album “All These Years,” which included appearances from all its former members – the groundbreaking Irish-American band Solas is about to head back out on the road, with a stop at the Cabot Theatre in Beverly on Feb., 18 at 8 p.m. (Go to thecabot.org for tickets and other details.)
But after that, don’t count on seeing them again anytime soon.

Recently, the band announced on its Facebook page that it will take a sabbatical for an undetermined interval after this tour – which kicks off on Feb. 9 and concludes on March 19. “It is time to hit the reset button and rest, write, teach, be with family and loved ones, and just breathe. This isn’t goodbye forever, necessarily, but it is goodbye for a while.”

Fiddler Winifred (Win) Horan – who is one of the two remaining original members of Solas, along with Seamus Egan – affirmed the decision last month in a telephone interview from New York City.

“Doing the album was a pretty big undertaking, what with having so many people involved: We had to record in a few different locations, based on people’s availability, and we never actually got everyone in the same place all at once,” she said. “When it was all done, I think it just hit us – especially Seamus and me – what a milestone this was for the band. And it was a reminder of all the effort, dedication and, yes, sacrifices we made to keep Solas going – it was all worth it, of course, because we saw the world, and played in places I’d never imagined.

“But through all that, as a band we never took a break, even though we have other projects and other important parts of our lives – I love the teaching I do at the Lincoln Conservatory, and I just don’t feel right not being there for my students. So, we don’t know yet how long this sabbatical will last, just that for a variety of reasons we need it.”

The birth of Solas in the mid-1990s represented a convergence of several trends, notably the arrival of a new generation of performers in the Irish/Celtic music revival that had taken hold by the late 1960s/early ’70s, as well as an increasing interest in exploring commonalities across musical genres. Add in the undeniable buzz that “Riverdance” – which debuted at around the same time – created for Irish music and dance, and it was a propitious time for a group of young Irish and Irish-American musicians to put a new gloss on the revival.

And that they did. Irish music aficionados and casual listeners were struck by Solas’s power and drive, its ambitious, forward-thinking arrangements, and most of all the sheer excellence of its members: from the enchanting, expressive voice of Karan Casey to the pulsating guitar presence of John Doyle to the melodic heft of Horan, Egan and his multiple instruments, and accordionist John Williams. Over time, the roster changed: Casey, Doyle and Williams departed; Donal Clancy and Mick McAuley arrived, with Eamon McElholm coming on board after Clancy left, Johnny B. Connolly after McAuley; and Casey’s role as lead vocalist was taken on in succession by Deirdre Scanlan, Mairead Phelan, Niamh Varian-Barry, Noriana Kennedy, and most recently, Moira Smiley. But Solas’s high-level ability and vision never faltered.

It’s not unreasonable to see the band’s growth and development as a microcosm of the Irish music revival itself. Starting from a largely traditional Irish repertoire, Solas reached into the American folk songbook (“Pastures of Plenty”) and the works of contemporary songwriters like Jesse Colin Young (“Darkness, Darkness”) and Sarah McLachlan (“I Will Remember You”), and increasingly revealed their own talents for composing tunes and songs. In doing so, Solas established an identity as not simply an Irish band, but an Irish-American one – its members native-born Irish or American-born of Irish immigrants – threading together styles and influences of both traditions.

Theirs was, and remains, a truly original sound perched comfortably between traditional and modern – one that is quite evident on “All These Years.” In some ways, it’s a retrospective, because not only are current and past members included, but other musicians who have sat in on various occasions: bassists Chico Huff and Trevor Hutchinson and percussionists Ben Wittman and John Anthony. Yet with the exception of “Darkness, Darkness,” all the material is new.

Egan’s command of various instruments – banjo, mandolin, flute, whistle, nylon string guitar – and Horan’s guts-and-glory lead and backing lines anchor the instrumental sets such as “Roarie Bummlers,” “Mr. and Mrs. Walsh” and “Lucy Locket’s/The Quiet Pint/The Sleepy Sailors,” with characteristic tight ensemble playing and shifting time signatures and rhythms from beyond the Irish and American traditions. The Francoesque waltz “Lost in Quimper” shows the band’s cosmopolitan side, with accordion, fiddle and mandolin teasing out the tune’s melodramatic disposition. And Solas even has a go at a classic session tune, “New Rigged Ship,” enhanced by a solid bass and percussion accompaniment.

The songs on “All These Years,” including the aforementioned revisit of “Darkness, Darkness” (led by Smiley), are equally impressive. Casey leads on two of them, the traditional “Sixteen Come Sunday” (sung with Doyle) that recalls but does not imitate the renowned Bothy Band version, and Patty Griffin’s tragic yet consoling “You Are Not Alone.” Lesser-known songwriters also get attention: Montanan Martha Scanlon’s “Little Bird of Heaven,” and Cork native Ger Wolfe’s “Lay Me Down,” given exquisite treatment by Smiley. Kennedy, accompanied by her five-string banjo, gives an Appalachian flavor to a setting of Yeats’ “Song of the Wandering Aengus,” and Barry’s rendition of Southern mountain ballad “Willie Moore” is in similar Irish-American territory, while Scanlan essays the sorrowful Irish nationalist lament of old, “Padraig Og Mo Chroi.”

“We didn’t want a repeat of what we did for the 10th anniversary, a live show with old material,” said Horan. “We wanted to look forward, not backward. This was a way of celebrating what we accomplished, with all the people who over the years brought their own unique gifts and energy to Solas; we thought it was better to put all these qualities to work on crafting something new. And I think the result shows how musically cohesive Solas has always been, regardless of who’s been in the line-up.

“To this day, I believe that with Solas it didn’t matter what your background was. None of us ever felt pressure, or an obligation, to fill a niche. What spoke to us from the beginning was the power of the music, the beauty in its simplicity, or its complexity. The music always came first.”

A band is a reflection of the time and circumstances in which it’s created, Horan said, and of how these intersect with the interests of the band’s individual members. “With Solas, you had five people who, although each had a foundation in Irish music, had eclectic tastes. John was into rock-and-roll, Karan was interested in jazz, and Seamus – though he grew up playing in the All-Ireland competitions – was a self-taught renaissance man who had an ear for arrangement and composing. I’d played Irish fiddle as a kid but also went to conservatory, and I grew up in New York City, exposed to a melting pot of sounds.

“Then you consider the 1990s, and what was going on, whether it was grunge rock, or groups like Afro-Celt Sound System blending Irish and world music, and of course ‘Riverdance’ with all the diverse influences in Bill Whelan’s musical score. Plus you had the Internet, though it was still kind of new, and you could get your ears on practically anything.”

So while early on the band might have adhered to a more trad Irish repertoire, Horan said, they felt no hesitation in broadening the scope of either form or content. “We always embraced that eclectic side of ourselves. We felt right doing it, and it was something that audiences clearly wanted to hear. So we just didn’t set any limits: If it was musical, and if it felt right, we’d do it.”

But doing it in the recording studio was never enough, she adds.

“Solas, from the get-go, was a touring band at the heart. Regardless of the technology you use, the training or the gear you have, if you can’t play and deliver live, if you can’t connect with an audience it doesn’t mean anything. That’s why I’m glad we’re touring for ‘All These Years’ – it’s very special to get a response from our fans who’ve supported us for so long.”

Appropriately enough, “All These Years” concludes with the title track, a hushed, reflective Egan composition played as a duet by Horan and Egan (this time on piano, which likely pushes his instrument count well into double figures).

“Putting it at the end just seemed the right thing to do, where it’s just Seamus and me,” said Horan. “It gets back to what I said about the simplicity of the music: Solas can have a ‘big sound’ with all kinds of things going on, but then we can have just two people playing something that’s quiet and mellow, and the energy and passion are still there.”

If “All These Years” – the album and the tune – isn’t a coda for Solas, exactly, it does herald a significant pause in the proceedings, according to Horan. At a time when the US and much of the world seems unsettled, socially, politically and even emotionally, Horan feels that the forthcoming hiatus is a much-needed opportunity to “look at what’s going on around us, not as a musician, but as a person.”

Still, she added, there’s ample reason to believe Solas can and will reconvene at some point in the near future and pick up where they left off.

“I just hope this time off lets us breathe, individually and collectively,” she said, “and helps catalyze our creativity.”