For the Cassidys, music has been a family business from the very beginning.
"One of my brothers has said that our earliest experience was hearing an O'Carolan concerto in the (crib)," Feargus Cassidy said by phone from Philadelphia. Feargus is one of six Cassidy brothers--along with Odhran, Seathrun, Aongus, Ciaran and Siontan--who are performing together on a national tour that includes a stop today at Orange Coast College in Costa Mesa.
The Cassidys play traditional Irish music, as might be suggested by that lineup of names and by the reference to O'Carolan, a 17th-Century Irish harpist-composer. The group's repertory ranges from old favorites to obscure airs and ballads rescued from the country's rich musical past, along with a growing selection of their own compositions.
They grew up in Ireland's rugged western coastal territory of County Donegal, where their father and mother steeped them in Gaelic culture and music.
"A lot of the tradition comes down to us through our parents," said Feargus Cassidy. "Music was always part of our family life."
Their father, Sean Cassidy, conducted the Gaelic choir--which all 10 children took part in--at their church on Sundays, and afterward they would gather to practice their music. Sean, a fiddler, has remained involved with his children's career.
"He has a great knowledge of Irish music," said Cassidy. "He's our harshest critic. Whenever we play, he is the person who is most difficult to please."
He also helps in researching some of the forgotten gems of Irish music that the brothers play alongside the favorites. That came in especially handy when the group recorded "1691," a historical theme album that came out in 1991.
The album collected songs relating to Patrick Sarsfield, who played a leading role in the Irish Roman Catholic resistance to England's King William III. The Jacobites, as they were called, were forced to surrender after their defeat in a battle at Aughrim in the year of the album's title.
That defeat preceded a rapid decline in Gaelic language, music and culture. "The way of life changed completely after 1690," Cassidy said. "In a way we wanted to recapture the old Gaelic order before the change."
In a nod to that order, the group sings many songs in Gaelic, which the family spoke as its everyday language. Its ties to tradition do not prevent the group from putting a distinct stamp on its arrangements, however, with elements of modern folk and other musical textures.
The six members of the group now active (the lineup fluctuates) all sing and all play a variety of instruments, including such Irish staples as \o7 uilleann \f7 (elbow) pipes (an Irish variant on the bagpipe), fiddle, \o7 bodhran \f7 (an Irish drum), accordion and bouzouki, as well as occasional modern touches, including synthesizer and bass.
"We find that different kinds of songs require different kinds of arrangements," Cassidy explained.
Despite playing together informally for years, and undertaking classical-music training, the family did not perform professionally until one summer on the island of Valentia in County Kerry, when, as Cassidy put it, "we got sort of hungry and thirsty."
A one-night stand at a local hotel turned into a summer-long engagement, and the Cassidys have been performing all over Ireland since, with regular appearances at the National Concert Hall in Dublin, the city where the group now makes its home.
In recent years, the group has been making tours to the United States, first conquering the Irish strongholds of the East Coast and moving slowly westward on each successive tour. Today's concert in Costa Mesa is its first in California.
The group also continues to record. Its most recent disc, "The Cassidys," collects selections from earlier albums and matches them with new recordings.
Cassidy attributes the enduring popularity of Irish music to its "phenomenal melodies" and to its emotional range. "I think there's a joy, but there's also a great deal of sorrow there," he said.
"Music in Ireland is part of the people. It's not just a group deciding to be a group--everyone in Ireland feels a part of the music. And it's fun, you know. You can have this in a pub or in a concert hall."
\o7 * The Cassidys perform Irish music today at 2:30 p.m. in the Robert B. Moore Theatre, Orange Coast College, 2701 Fairview Road, Costa Mesa. $10 to $13. (714) 432-5880.\f7