The Going Out Guide recommends free things to do this week.

Chef Devin Alexander will be in town passing out free samples of a walnut dessert this week. (Photo by Hiero) Chef Devin Alexander will be in town passing out free samples of a walnut dessert this week. (Photo by Hiero)

Chef Devin Alexander

In partnership with California Walnuts, chef Devin Alexander, known for her role as the chef on NBC's "The Biggest Loser," will be preparing snacks and sharing tips for staying healthy during the summer at two locations in the District.

Friday. 6 p.m. to 9 p.m. The Yards Park, 355 Water St. SE. www.yardspark.org. and Saturday. Noon to 5 p.m. The parking lot of PNC Bank, 1201 Wisconsin Ave. NW. www.walnuts.org.

This week in free concerts:

Vijay Iyer and Rudresh Mahanthappa

In conjunction with the exhibition "Beyond Bollywood: Indian Americans Shape the Nation" (at the National Museum of Natural History through Aug. 16), award-winning pianist Vijay Iyer and alto saxophonist and composer Rudresh Mahanthappa join forces for a jazz concert.

Thursday. 7:30 p.m. Freer Gallery of Art, Jefferson Drive and 12th Street SW. 202-633-1000. asia.si.edu. Free, tickets required.

FBCG ID Young Adults

First Baptist Church of Glenarden's young adults ministry invites adults ages 18 to 35 to an event featuring performances by Black Alley, Marlee in the Mixx and Musically Yours. There will also be food trucks on site.

Saturday. 6 p.m. First Baptist Church of Glenarden, 3600 Brightseat Rd., Landover. www.fbcglenarden.org.

Tunes in the Triangle: Andrea Pais and Alison Carney

Singer-songwriter Andrea Pais left a career in engineering to pursue music. She is a classically trained pianist and District native with a sound that blends R&B, soul and pop music. Alison Carney was raised in Washington. In 2011, the singer-songwriter released a mixtape called "AlisonWonderland." Hear these two perform live as part of the Tunes in the Triangle concert series.

Thursday. 11:30 a.m. to 1:30 p.m. (Pais) and Carney 6 p.m to 8 p.m. Mount Vernon Triangle, Fifth and K Streets NW. www.mountvernontriangle.org.

This week in free movies:

Bethesda Outdoor Movies

The final screenings of the 10th annual film festival will be "Mrs. Doubtfire," the classic 1993 film starring the late Robin Williams; and "Imitation Game," the 2014 film based on the story of Alan Turing starring Benedict Cumberbatch and Keira Knightley.

Friday and Saturday. 9 p.m. Woodmont Triangle, Norfolk and Auburn Avenues, Bethesda. www.bethesda.org.