It's a vibrant weekend in Somerville, with four festivals and a grand opening celebration for a local institution.

Here's a rundown of some festival happenings in Somerville this weekend.

Greek Music and Food Festival
Greek food, music and culture is on hand throughout the weekend. This festival begins Friday at 5 p.m., and it continues on Saturday and Sunday, starting at 12 p.m. those days. You can try wide variety of Greek food accompanied by live Greek music, and the festival has the best loukoumades in Boston, according to the event's poster. There will also be tons of dancing. To join the fun, go to Dormition of the Virgin Mary Greek Orthodox Church at 29 Central Street.

Brasileiro! Brazilian Festival
Somerville will celebrate its significant Brazilian community with food, music, dancing, activities, Brazilian drummers and—no Brazilian festival is complete with out it—a soccer competition.

You can get free samba lessons, dance to live music and stuff your face with Brazilian barbecue.

Brasileiro takes place Saturday in Union Square from 3 p.m. to 7 p.m.

Rolling on the Mystic
Go canoeing on the Mystic River, check out a marionette show, listen to some music, partake in some children's activities (if you're a child), and enjoy walking, biking and skating along Shore Drive, which will be closed down to traffic, for the SomerStreets Rolling on the Mystic festival. The festival is Saturday, from 12 p.m. to 4 p.m., on Shore Drive.

85th annual Italian Festival of The Healing Saints Cosmas & Damian
This East Cambridge Italian festival will dip its toes into East Somerville on Sunday during the great procession. One of New England's largest Italian festivals, Cosmas & Damien takes place on Saturday and Sunday on Warren Street in East Cambridge. There will food, amusements, parades and a number of performances, including one by American Idol star Ayla Brown. On Sunday, Saints Cosmas and Damian will be paraded through East Cambridge and East Somerville accompanied by the Saint Alfio Band and the North End Marching Band.

Mudflat grand opening
Mudflat Studio has a new building at 81 Broadway in East Somerville, in the old Broadway Theatre. The pottery and clay organization is celebrating the grand opening of its new digs Saturday from 12 p.m. to 4 p.m. In addition to a ribbon cutting, there will be live music, pottery demonstrations and an exhibition of clay artwork. Also, you can help decorate a huge clay pot that will adorn the new building.