The Olney Theatre Center is known for thinking outside the box with its programming, but this weekend's InCite Festival is something special. Boston University performers invade Olney for a weekend of unconventional theatrics. "Every Good Boy Deserves Favour?" features an entire chamber orchestra, and the opera "The Man Who Mistook His Wife for a Hat" is as wacky as it sounds. Both productions will be staged tomorrow and Sunday . . . If you prefer your orchestras to play by without actor accompaniment, head to Strathmore tomorrow night for the National Philharmonic's "Three B's Concert." Even just casual fans of classical music know the Three B's are Bach, Beethoven and Brahms. Pianist Brian Ganz, cellist Zuill Bailey and violist Elena Urioste will hit a highlight of each composer's catalogue, climaxing with Beethoven's "Triple Concerto." . . . Yes, some cerebral fare, like "An Education," is hitting movie theaters this weekend, but tomorrow is the day of witches and spooks. So pass on the brain candy for a few good scares. "Paranormal Activity" is the greatest indie-horror phenomenon since "The Blair Witch Project." Last weekend, it scored the No. 1 box office slot. Right behind that film was "Saw VI." If you have already seen both, there is always the Ringo Starr of the '80s horror revival, "The Stepfather." . . . Have a great weekend, and remember: Sending your child into the night wearing a black sweat suit and calling him "The Invisible Man" is never a good idea.