By Toby Zinman

Pig Iron Theatre Co, — the crown princes of the radical avant-garde -- goes mainstream: This year it's Shakespeare, the comfy Suzanne Roberts Theatre, the works. Which is not to say their Twelfth Night is not a wild rumpus of a show, full of wailing gypsy music (by Rosie Langabeer) played by an (overused) band, and stuffed with terrific performances.

Shakespeare's Twelfth Night  is about twins, gender-confusion, and love — passionate, crazy, I'll-die-if-I-don't-have-you love.  Pig Iron's Twelfth Night is also about all that stuff, but gives the drunks, the cruel noblemen, and the rude servants much more stage time.

One of the many casting triumphs is that Sarah Sanford (splendid as Viola  disguised as a boy) and Blake DeLong (playing her long-lost twin brother Sebastian) look ridiculously alike. Another is Dito van Reigersberg's Duke Orsino is hilariously elegant.

But the surprise is Scott Greer as Feste the Fool. It is a brilliant and subtle and funny performance, and never have I heard the delicate "Hey Ho the Wind and the Rain" sung more movingly.

The messy set (designed by Maiko Matsushima) makes great use of a skateboard ramp as characters use it to zoom in and out. Dan Rothenberg directs with his usual bizarre élan.

$15-30.  7 p.m. 9/7 and 8, and 9/13-15; 6 p.m 9/9 and 16; 2 and 8 p.m. 9/10 and 17; 1 and 7 p.m. 9/11. Suzanne Roberts Theatre, Broad and Lombard Streets.