Decibel Fest’s Optical showcases, of which there are five this year, are designed to interweave visual elements into musical performances—for example, on Wednesday, September 26 at the Broadway Performance Hall, the ambient British duo Demdike Stare will perform a live re-scoring of the 1970 cult horror film La Vampire Nue. Tonight’s event, ASCENSION, will feature visuals by the filmmaker and illustrator Christina Vantzou (she’s also a musician who released her debut solo album Nº1 late last year) projected during a performance by the singular New York vocalist Julianna Barwick. Barwick released her exquisite album The Magic Place in 2011 and followed it by forming OMBRE, a duo with her Asthmatic Kitty labelmate Helado Negro; they released their fleecy Believe You Me record in August. For a showcase called ASCENSCION, Barwick’s angelic, vertiginous vocals are the perfect fit. With Maria Minerva, Anenon, Lulacruz. ERIN K. THOMPSON

Thu., Sept. 27, 7 p.m., 2012