CELTIC THUNDER8 p.m., Alltel Arena. $37.50-$57.50.
Here's something you don't hear much in this day and age: Celtic Thunder,
the five-man Irish vocal group, is a bona fide PBS-fueled phenomenon. So far in 2008, the network has aired the group's live show more than 1,000 times. Who knew traditional Celtic music (that is, music rooted in Ireland and Scotland) had such an appeal? Though, to be fair, Celtic Thunder isn't all “Whiskey in the Jar.” The vocal group, spanning in ages from teens to middle age, is known, too, for adding regional flair to more contemporary songs like “Nights in White Satin” and “Ride On.” Expect, also, elaborate choreography and visual effects and accompaniment by the bagpipes, the Celtic Concert Orchestra and monks.