Free (mostly classical) concerts Friday and Saturday.

Start the weekend with Beethoven’s “Symphony No. 7” at 8 p.m. Friday at the Massachusetts Institute of Technology’s Kresge Auditorium, 48 Massachusetts Ave., performed by the school’s IAP Orchestra, conducted by Dominique Hoskin; enjoy the Complete Brahms Sonatas for Violin and Piano from 8 to 10 p.m. Saturday at Edward M. Pickman Hall at the Longy School of Music, 27 Garden St., Harvard Square, performed by Paganini Competition prize-winner Kowoon Yang and Longy faculty artist Esther Ning Yau; or hear Australia’s leading youth choir, the Gondwana Chorale (above), sing from 7:30 to 9 p.m. Saturday at First Church in Cambridge, 11 Garden St., Harvard Square.

The ninth annual “Some Like it Hot” Chili Cook-off from 1 to 2:30 p.m. Saturday on Brattle Plaza, Harvard Square. Free.

This Super Bowl precursor offers “Hot, Spicy, Vegan, Traditional and Exotic” free samples of chili from Harvard Square restaurants including Beat Brasserie, Crema Café, El Jefe’s Taqueria, En Boca, Grendel’s Den, J.P. Licks and The Sinclair, with the winner of the most samplers’ votes getting the Harvard Square Chili Pot for the year. There will be live music from Grooversity, which combines the Brazilian sounds of samba and axe with funk, rock, jazz and hip-hop. Information is here. (Can’t go? There’s more grub the next day at the free 12th Annual Great Chili Cook-off from noon to 3 p.m. Sunday at Olde Magoun’s Tavern, 518 Medford St., Magoun Square, Somerville.)

Silent Disco Snow Day from 2:30 to 6 p.m. Saturday, starting outside the Charles Hotel, 1 Bennett St., Harvard Square. Free, with the first 40 people to RSVP getting free earmuff headphones.

Go on a one-mile silent dance walk – that is, you’ll hear music in your headphones, but no one who isn’t wearing the headphones will – through Cambridge and Allston, winding up at a secret location after-party with hot food and drinks from Whole Foods Market, Stone Hearth Pizza and DavidsTea. (Access is first-come, first-served at the party for the first 130 people showing up at the hotel.) Information is here.

Out of the Blue Benefit Show from 8 p.m. Saturday to 1 a.m. Sunday at Out of the Blue Art Gallery Too, 541 Massachusetts Ave., Central Square. Admission is $10 or pay-what-you-can, which goes to helping the gallery pay the bills.

Help this community art gallery and venue for all-ages rock shows by checking out some standup comedy by Justin P. Drew and music by Climate Change (at 9 p.m.), Clash tribute band Charlie Don’t Surf (10 p.m.), State of the Union (11 p.m., seen above) and Dennis Most and the Instigators (midnight). Information is here.

Pre-Superbowl Show with music from 2 to 6 p.m. Sunday and the #SnarkerBowl/Chili Cook-off Party from 6 to 10 p.m. Sunday at Aeronaut Brewing, 14 Tyler St., near Union Square, Somerville. Free.

Show up early with your own picnic to enjoy music from Paul (of Mailman Carl) at 2 p.m., Miketon and the Night Blinders at 3 p.m., Bredon Jones at 4 p.m. and Lenny Solomon at 5 p.m. Then the brewery invites chili cooks to bring in plastic containers full of their best stuff for a taste-off in which judges will award prizes for Best Vegetarian, Most Spicy and Best Overall chili. And there’s even a football game to watch on three giant projection television screens – with an added tweetwall where comedians Dana Jay Bein and Katie Qué (above) will be live tweeting the Super Bowl and halftime commercials. Information is here and here.