Aggregation No. 1NorthAmericana Festival at 7 p.m. Friday at Passim, 47 Palmer St., Harvard Square, with $18 admission (or $15 for Passim members) and from noon to 9 p.m. Saturday on Brattle Plaza, Harvard Square, for free.

More than a dozen of the region’s established and up-and-coming Americana artists perform in this inaugural event backed by legendary folk club Passim and the Harvard Square Business Association. Paid performances are by the Chuck McDermott Band (including Kevin Barry, Richard Gates and Duke Levine) with Jay Psaros opening. The day of free performances in the heart of the square begins with Tony Savarino & The Savtones at noon and continues with Lula Wiles at 1 p.m.; Citizen Slim at 2 p.m.; The Wolff Sisters at 3 p.m.; Comanchero at 4 p.m.; Julie Rhodes at 5 p.m.; Miriam at 6 p.m.; Patrick Coman and Peter Parcek at 7 p.m.; and The Silks Music at 8 p.m. Information is here.

Aggregation-ornament-478

091516i-curious-george

Aggregation No. 2Curious George’s 75th Birthday Bash from 2 to 5 p.m. Saturday on Palmer Street, Harvard Square, across the street from The World’s Only Curious George Store, 1 John F. Kennedy St. Free.

With the children’s book monkey turning 75 and The World’s Only Curious George Store threatened by development, it seems like a good time to celebrate what the character – created by Cantabrigians Hans and Margret Rey – has meant to the city. The Harvard Square Business Association is helping throw this party, and Mayor E. Denise Simmons plans to present a proclamation at 2:30 p.m. declaring it “Curious George Day” in Cambridge. Otherwise it’s all fun and calories: meeting the monkey himself; birthday cake and cookies compliments of The Charles Hotel, Chunky Monkey ice cream compliments of Ben & Jerry’s Ice Cream of Harvard Square and bananas and chocolate dipping sauce from the HSBA; a bit of singing; and games, activities and arts and crafts for kids. The store has 75th anniversary commemorative books and collectibles, and guests are encouraged to bring a gift of a new toy or book to donate to Cambridge Family & Children’s Service. Information is here.

Aggregation-ornament-478

091516i-now-listen-here

Aggregation No. 3Politics and Red Tape: Stories of Jumping Through Hoops” at 8 p.m. Saturday (doors at 7 p.m.) at Gallery 263, 263 Pearl St., Cambridgeport. There’s a suggested donation of $10.

Storytelling newcomers and veterans organized through Now Listen Here share tales of bureaucracy and partisanship – at work, in school, around the dinner table or anywhere else – for six to eight minutes at a time in this intimate, artsy setting. Information is here.

Aggregation-ornament-478

Aggregation No. 4“Star Wars: The Force Awakens” from 8 to 10 p.m. Saturday at Harvard’s Science Center Plaza between Harvard Yard at Kirkland and Oxford streets, near Harvard Square. Free.

The latest “Star Wars” movie gets a free, open-air screening under the Science Center Plaza tent, with light refreshments and seating provided by sponsors Common Spaces, the Harvard-Radcliffe Science Fiction Association, the Undergraduate Council and the Office of Student Life. Participants are also invited to bring a blanket and a pillow. Information is here.

Aggregation-ornament-478

091516i-revels-riversing

Aggregation No. 513th Annual Revels RiverSing from 5 to 7:30 p.m. Sunday in Harvard Square and by the Weeks Footbridge along the banks of the Charles River. Free.

Cambridge’s traditional sendoff to summer and welcoming of the months of foliage, Halloween, apple cider and hot chocolate is here, led as it has been for the past decade by the nonprofit Revels organization. It includes the 100-member RiverSing Chorus of adults and children, a high-energy percussion ensemble, a folk band and the raucous JP Honk! band, as well as guest soloists including jazz great Stan Strickland, Bluegrass musician Howie Tarnower; singer/songwriter Bret Silverman; and saxophonist Ken Field. Acrobats and street performers will keep things lively and giant puppets from Sara Peatie’s Puppeteers Cooperative and the magical butterflies of Gabriel Q will add to the magic. It starts with a 5 p.m. gathering in Winthrop Park for family festivities including Honk! band music, face painting and hula-hooping. At 5:45 p.m. comes a parade to the Charles River for 6 p.m. singing and poetry along the Charles. Information and printable lyrics – many audience members sing along – are here.