Tears of Joy Theatre Cultural Centre Studio Theatre. July 16. ONCE upon a time there is a collection of very strange birds, the programme informed. ''They dance, explore and find new ways to look at the world around them.'' Syntax aside, it was soon apparent that the blurb about the third and final piece from the company chosen to open the Urban Council's 1993 International Arts Carnival was grossly misleading. Granted, a couple of extra ornithological oddities made their appearance of the end of Boogie Birds, but that was just to lure youngsters on stage for a hands-on finale. What the programme should have said was something like: ''One day during his lunch-break, a big bully meets the Boogie Bird and decides to have some cruel fun. 'Okay, let's boogie,' thinks the Boogie Bird. Guess who has the last laugh!'' There were no tears, but what a joy to see the art of puppetry presented with such finesse. Imagine a cross between a tufted bath-mat and a drag queen, and you'll have a rough approximation of the Boogie Bird. What the kids saw was a deliciously droll creature who was game to go to any lengths - walk a tight-rope, hurtle across chasms, hang by a claw - for a chance to get its greedy beak into the tormentor's bag of goodies. It was the sharpest, funniest piece presented by the acclaimed American troupe. Also the most successful in terms of general audience appeal. Had it been an predominantly English-speaking audience of under-eights, honours might have gone to There's A Nightmare In My Closet, but while Michael and his teddy were easy to identify with and the Nightmare turned out to be a hoot, the recorded voice of Michael fell on a lot of bemused young ears. Occupying the first half of the programme was the much-lauded Petrouchka. With its story-within-a-story, this was by far the most complex, demanding piece and one could only marvel at the puppeteers' skill and versatility. As anyone familiar with hand-held puppets will know, it takes years to perfect realistic, synchronised movement and Tears of Joy didn't miss a beat. Amazingly, Reg Bradley and his troupe also managed to conjure a Russian carnival full of entertaining acts and demonstrated real brilliance with masks and costumes while they were at it. For all that, Petrouchka fell a little flat. The Boogie Bird's moral: never make it look too easy.