http://www.youtube.com/watch?v=2hovKm9oFiM

Watch a hell of a lot of movies for a good cause. The Brattle Watch-A-Thon Movie Fundraiser is back, benefiting the Brattle Film Foundation and ensuring the historic theater keeps serving film lovers in Harvard Square. The event starts at noon Saturday with Tim Burton’s “Beetlejuice” and runs through a special secret midnight screening, doing it again from noon to midnight Sunday with a  different set of flicks. Film include cult classics such as “The Terror of Tiny Town,” “Big Trouble in Little China,” genre pieces such as “The Wild One” and classics such as “Gentlemen Prefer Blondes.” All-day passes are $40 (or $30 for students, Brattle members, seniors or children under 12) or $8 and $7, respectively, per film. The Brattle Theatre is at 40 Brattle St., Harvard Square. More information is here.

Follow the sounds of Honk! to Oktoberfest. The eighth annual grassroots, nonprofit Honk! Festival of Street Bands is under way throughout Boston, Somerville, and Cambridge – more than 500 musicians in some 23 eclectic, eccentric and joyous bands that include Somerville’s own Emperor Norton’s Stationary Marching Band and troupes from as far away as Boulder, Colo.; Austin, Texas; Rio; and London. Honk! is pumping up the volume from 12:30 to 9 p.m. Saturday in Somerville’s Davis Square, then marching from noon to 2 p.m. Sunday in The Honk! Parade (to “Reclaim the Streets for Horns, Bikes and Feet”) to Harvard Square, where they provide the soundtrack for Oktoberfest until 6 p.m. More information on Honk! is here.

This 35th annual Oktoberfest is expected to draw 200,000 people to sample its six stages of musical entertainment, 50-plus food vendors and four beer gardens and more than 150 stalls of arts, crafts and other gift items. (There is also a promised noon performance in Harvard Square by “a special surprise duo that has been making waves across the country.”) More information is here.

See who made it from the red carpet to the artist’s canvas. Back in May, painter Danielle Festa literally put down a red carpet in Union Square and asked people to pose for photos in their favorite street fashion. Festa, who had a Somerville Arts Council Fellowship Grant for the project, would then turn those images into paintings. Well, the mixed-media oil paintings are here, on display from 2 to 5 p.m. Saturday in Union Square Plaza, Somerville, with hors d’oeuvres from Cantina La Mexicana and Sweet Ginger. More information is here.

Check out that moon. It’s Moonapalooza! The Harvard-Smithsonian Center for Astrophysics is offering a free peek at our celestial back yard at 7 p.m. Saturday as part of International Observe the Moon Night. There will also be a general-audience moon trivia contest with prizes and a drawing for an Orion XT4.5 Dobsonian reflecting telescope for kids ages 6-14. The event is at Phillips Auditorium, 60 Garden St., about 1 mile west of Harvard Square.  More information is here.

Getcher $5 classical symphony concert culture here! While Honk! is marching around and enlivening our streets for free, you can shift into high-culture gear for a mere $5 with an MIT Symphony Orchestra concert from 8 to 10 p.m. Saturday. The bill: Brahms’ “Variations on a Theme by Joseph Haydn, Opus 56”; Haydn’s Symphony No. 45 in F-sharp minor, “Farewell”; and Mussorgsky’s “Pictures at an Exhibition” as arranged by Ravel. The concert is at the Massachusetts Institute of Technology’s Kresge Auditorium, 48 Massachusetts Ave. More information is here.