In a look ahead at a week of Cambridge and Somerville events, Jonathan Katz and other local comedy greats perform a fundraiser for MS research, the Songs of 1980 play at Club Passim, you can make your own video Valentine, Gish Jen reads, there’s free music, cheap poetry and much more.

A look ahead at a week of Cambridge and Somerville events brings the Once in Valhalla 10-course feast, followed Sunday by free chili cook-offs in both cities, as well as an evening with Sutton Foster in Sanders Theatre, the return of “Medusa: Reclaiming the Myth” and much more.

In a look ahead at a week of Cambridge and Somerville events, there’s the dystopian dance musical “iTMRW” and “Das Kapital” play performance, opera with “Aida” and more, and “Somerville Night Live.” It all starts with an MLK flash mob dance on the Monday holiday.

In a look ahead at a week of Cambridge and Somerville events, Club Passim celebrates Irish, Scottish, Cape Breton and other Celtic music, Patricia Marx and Roz Chast bring their “Rules For Couples,” Callie Crossley kicks off Atwood’s Interviews, The Human Variety Hour premieres and much more.

In a look ahead at a week of Cambridge and Somerville events, there are returning theater events such as “Club Drosselmeyer 1942” and “The Slutcracker,” an ice sculpture stroll, a snow globe workshop and Trashion show, tons of poetry and music, and more.

In a look ahead at a week of Cambridge and Somerville events, there’s the final concerts for the Childsplay fiddle troupe, the Found Footage and Weird Local Film festivals, May Phillips poetry, a ton of free music ranging from Bach to “Super Mario,” puppets and more.

In a look ahead at a week of Cambridge and Somerville events, there are “Hamlet,” “Twelfth Night” and “West Side Story” performances, not to mention the whole Boston Comedy Festival, immersive “One You Feed” dance, Native American poetry, arm wrestling and more.

In a look ahead at a week of Cambridge and Somerville events, the Bread & Puppet Theater is back and there’s Indonesian Shadow Theater as well, Lindy West is in town to read, the Kendall Square Orchestra performs and the affordable Art Outlet pops up.

In a look ahead at a week of Cambridge and Somerville events, there’s a Comedy Studio Festival of Dad Jokes, the annual Fuzzstival of local and regional bands, murder mystery improv, a Greek fest, plenty of poetry and a slew of authors, including Janaka Stucky.

In a look ahead at a week of Cambridge and Somerville events, there’s the 40th Cambridge Arts River Festival, Big Gay Dance Party, Carnaval Somerstreets, “Happy Hour: Secret History of Boston’s Suburbs” from Dig and CityLab, “Gaslight” and much more.