Hassle 24-Hour Telethon & Performance Marathon from 10 a.m. Friday to 10 a.m. Saturday at the Somerville Community Access Television studios, 90 Union Square, Somerville. Free.

The Boston Hassle arts group is fundraising to sign a lease for an all-inclusive, all-ages art market, community center and performance space, and to inspire donations have put together a full 24 hours of entertainment that includes comics such as Katie McCarthy and Rob Crean, bands such as Spectramotiv and Divided Self, films, lectures and talks such as on “The future of capitalism,” performance artists such as Crank Sturgeon and Katie Lee Haley, drag, workouts, speakouts, poetry, regular storytelling as well as “weird storytelling” and even experimental bike percussion with Reynaliz Herrera. The performances are open to the public, but studio space is limited; the telethon can be watched via computer or device via SCATV or the Hassle’s site, but why watch alone? There are viewing parties from 1 to 5 p.m Friday at Cantina La Mexicana and from 5 to 11:55 p.m. Friday at Aeronaut Brewing, both in or near the station in Somerville’s Union Square. Information is here.

Live Band Emo/Pop Punk Karaoke at 8 p.m. Friday at the The Middle East Downstairs, 480 Massachusetts Ave., Central Square. Tickets are $10 to $14.

This goes way beyond your typical karaoke – in this case there’s a live band playing while you take the stage and belt out those songs you loved in middle school from the likes of Brand New, Sum 41, Taking Back Sunday, Blink 182 and Green Day. Information about this 18-plus show is here.

Slow Art Day is Saturday, with events from 11 a.m. to 4:30 p.m. at the Harvard Art Museums, 32 Quincy St., near Harvard Square (free until noon for Massachusetts residents); and from noon to 4 p.m. Saturday at the List Visual Arts Center, 20 Ames St. (free).

This local celebration of a global event lets art appreciators slow that appreciation way, way down – traditionally, to five works of art in an hour (or a goal of one every 10 minutes) from the 15 to 30 seconds the average museum visitor spends. There will be appreciation sessions at Harvard’s Fogg, Sackler and Busch-Reisinger galleries at 11 a.m. and 3 p.m. (and maybe in between), with information here. At MIT’s List, there’s a handout available from noon to 12:30 p.m. to provide visitors with a self-guided gallery viewing experience, with a facilitated group discussion at 3 p.m. to share observations and interpretations. Or, of course, just go look at art. Information is here.

“Transparent” improvised performance from 8 to 10 p.m. Saturday at Warehouse XI, 11 Sanborn Court, Union Square, Somerville (behind Journeyman restaurant, in the alley between the Independent and Bronwyn’s restaurants). There are tiered ticket prices based on what you can afford: $10.49, $14.71, $25.26 or $37.92.

This rough-hewn, recently converted warehouse space hosts artists who enter without preconceptions or plans and perform pieces as they are created, in real time, feeding off one another and creating moments that are both strange and universal. In the later part of the night, musicians are invited to bring instruments and join in, dancers are invited to take part and photographers and artists to capture the scene, but the evening starts with the inspiration of dancers Catherine Musinsky, Chien Hwe, Callie Chapman and Emily Jerant-Hendrickson; percussionist Syd Smart, drummer Giuseppe Paradiso and alto saxophonist Russ Gershon; and lighting by Todd Sargent with live projected video by Werner Grundl and Julie O’Neil. It’s all directed and produced by Catherine Musinsky. Information is here.

Perform-a-thon 2017 from noon to 5 p.m. Sunday at the New School of Music, 25 Lowell St., West Cambridge. Donations are expected for this fundraiser.

Start the weekend with a “thon,” end it with one too. This annual event raises operational funds needed for the New School of Music and its need-based scholarships for private lessons and group classes, educational programming and community concerts and maintenance of its music studios and instruments. Concerts take place at noon and 1, 2, 3 and 4 p.m. Information is here.