Friday: 9:15 p.m. Penobscot; Saturday: 1 p.m. Railroad

Karan Casey has one of the most instantly recognizable and original voices in Irish music. A former lead vocalist with the Irish supergroup Solas, she exhibits the grace and richness of an old soul. The Wall Street Journal calls Casey “one of the true glories in Irish music today.”

It is impossible to understate the importance of voice in Irish music. Generations of Irish singers have served as historians, chroniclers and commentators through their evocative stories and plaintive words. Casey has continued this tradition, singing about social issues as well as traditional English and Irish Gaelic songs.

Casey began learning about the drama of songs growing up in Ballyduff Lower, County Waterford. She was surrounded by music and encouraged to sing. Virtually adopted by the folk-singing Foran family, she was encouraged to enter local music competitions. She later discovered jazz and spent many hours listening to Nina Simone, Ella Fitzgerald and Billie Holiday. She went on to sing pop, jazz and Irish standards in pub bands. In 1994, Seamus Egan and Winifred Horan heard Casey sing with Atlantic Bridge in New York City and asked her to join a band they were forming, Solas. The group became one of the most celebrated Irish bands in the United States.

Casey understands the soloist’s unique niche and is cautious about the tradeoffs that come with singing to accompaniment.

“Traditional Irish music is a challenge,” she says. “I grew up singing on my own. I learned a lot of songs on my own and did solo singing competitions. And a lot of the tradition is about solo singing and drawing people into you and into the song.”

Casey blends songs from the traditional Irish canon and recent tunes as shown on her 2003 Shanachie release, “Distant Shore.” She notes that two of the songs, “Distant Shore” and “Bata is Bothar,” are about immigration.

“The tunes are about people coming to a new land and having to deal with that,” she says. “This is something I feel very strongly about. There are a lot of problems here in Ireland. We’re not really treating our immigrants very well, so these songs are a good way to talk to people about that subject.”

In 2001, Casey won Best Folk Album from Irish Music magazine and was nominated for a Grammy in Denmark in the category of Best International Folk Album. She was nominated for her song “Who Put the Blood” from “The Winds Begin to Sing” by the BBC Radio-Folk Roots Awards in the Best Traditional Track category.