Trinity Irish Dance Company At one time, only boys wore the hard-soled boots that produce the tapping of such dances as the hornpipe and reel; they were too expensive for poor Irish families to provide their girls. But now, even at official Irish dance competitions, girls can and do wear such shoes. And so what we may think of as immutable traditional forms change as the circumstances that created them change. Mark Howard, artistic director of Chicago’s Trinity Irish Dance Company, has done so well with the tried-and-true–in 1987 Trinity was the first American troupe to be named the World Champions of Irish dance–it seems he’s looking for new frontiers. “Damhsa: A Celtic Odyssey” will include not only the traditional stuff the company does so well but contemporary variations on it and pieces that branch out into other ethnic forms and modern dance. Lemon is a work in progress set to the U2 song of the same name. Umoja, which uses dancers from Natyakalalayam and Sundance Productions, combines the equally percussive but otherwise very different forms of Irish, Indian, and African dance. In Turf, Trinity will be joined by Chicago tap dancer Brill Barrett in a work that also dabbles in African boot dancing as filtered through hip-hop. It seems Irish dance has come a long way from the time when the Church considered it the devil’s work and tried to ban it. Somehow dance of all kinds has survived repression, and in our suddenly smaller world it’s mutating rapidly. Friday at 8 at Navy Pier’s Skyline Stage, 600 E. Grand; $18-$22. Saturday at 11 AM, also at the Skyline Stage, there will be a short, hour-and-a-half program; $5 for children 12 and under, $8 for adults. Call 902-1500 for tickets, 594-1115 for group sales.