Opportunities to see The Cremaster Cycle—Matthew Barney's five-part, astoundingly audacious art-film fantasia—are few and far between, but SIFF Cinema screens the whole glorious thing today. Among Cremaster's themes: Celtic myth, gothic Americana, and the impending descent of testicles. Throughout the six-and-a-half-hour cycle, the level of pretension is matched only by the meticulousness of the execution, adding up to a ravishing, occasionally maddening experience. (If you can see only one installment, make it 3, a three-hour dreamscape of choreographed cars, amputee muses, and Masonic ritual.) (SIFF Cinema, 321 Mercer St, www.siff.net. April 9–15.)