Pam and Philip Boulding have just stopped at the store to buy some juggling balls for their 26th annual Celtic Yuletide Concert series.

Juggling balls?

The Bouldings, aka Magical Strings, go all out for this series, bringing in their five adult children (and a few grandchildren) from around the country for concerts that have become a Northwest tradition.

They’ll perform Sunday in Shoreline.

A Magical Strings concert stretches beyond carols. Expect the Raney Irish Dancers, juggling, a Celtic storyteller with a seasonal tale, and many songs in what is often a 2-hour performance.

Be prepared to participate in the signature moment of this Yuletide tradition – the processional.

Dress up at intermission in colorful costumes supplied by the Bouldings and follow the musicians, dancers, drummers and jugglers around the hall and up and down the aisles.

Near the end, join in a holiday sing-along before the evening concludes with “All Through the Night.”

“Yuletide is a celebration that goes beyond the Christian tradition but it is inclusive,” Philip Boulding said.

“It’s a festival of the return of light after the longest night … a celebration of Earth coming back to life. It translates culturally through the various religions. In Christianity it got translated through the birth of Christ near the Solstice,” he said.

“It’s a festival necessary for renewal, a rejuvenation and acknowledgement of the striving of the human sprit in the midst of darkness.”

Boulding finds a particular need for the celebration this year.

“In this country where we’re facing incredible polarities of Republicans and Democrats, and pro-war and anti-war, and fear of terrorism and the agony of war, it’s a dark time for a lot of people.” he said.

“It’s important to have a festival to bring us back to our origins, and to ask who are we, what is our purpose, how do we renew ourselves? It’s a festival of hope, as well.”

The Bouldings play the Irish harp and the hammered dulcimer, once an unusual combination of instruments.

“It virtually wasn’t done in this country before Pam and I got together and created Magical Strings.”

Celtic music seems to reach deep into the soul.

“There’s sorrow and tragedy but there’s a catharsis that happens when you hear the music,” Boulding said.

Celtic instruments are an integral part of the appeal, especially the Irish harp. It’s music of remembrance, not step-dancing.

“The ancient wire-strung harp with brass strings has an amazing sound. It’s almost mystical,” he said.

“It’s the introverted instrument that provides the harmony. The dulcimer is the expressive, outgoing instrument, very much the extrovert (that provides) the melody. It’s a powerful combination.”

For Boulding, who makes harps and dulcimers as well as teaches (School of Magical Strings), the journey continues.

“I would like to take what I experience in the world and translate that through music. The world is in a pretty precarious place right now,” he said.

“Hopefully our compositions continue to grow and bring joy to a sorrowful world.”

The Magical Strings perform Sunday in Shoreline.

Magical Strings

3 p.m. Sunday, Shorecrest Performing Art Center, 15343 25th Ave. NE; $15; 206-417-4645. Also 3 p.m. Dec. 19, Lincoln Theater, 712 S. First St., Mount Vernon; $12-16; 360-336-8955.

Magical Strings

3 p.m. Sunday, Shorecrest Performing Art Center, 15343 25th Ave. NE; $15; 206-417-464. Also 3 p.m. Dec. 19, Lincoln Theater, 712 S. First St., Mount Vernon; $12-16; 360-336-8955.