Morris tells PEOPLE her outfit will give off "Almost Famous vibes" as a nod to Kate Hudson's iconic character Penny Lane

After a year of canceled concerts, festivals and events, Maren Morris is returning to the stage for a special occasion.

The country singer, 31, will be joining a star-studded lineup of performers at the second annual SHEIN Together Fest to be streamed via SHEIN's free app on Sunday, May 2 at 5 p.m. EST/2 p.m. PST. Along with Nick Jonas, Steve Aoki, Tinashe and Lunay, Morris will be going all-out for the epic virtual concert, which is tied to SHEIN's philanthropic Light-a-Wish campaign.

"I try to be very charitable, especially in this year," Morris tells PEOPLE when we caught up with the star at her rehearsal for SHEIN's Together Fest livestream. The fashion brand pledges to donate $300,000 to three different charities — NAACP Legal Defense Fund, Together We Rise and Ecologi (selected by its own community!) — in honor of the event.

Maren Morris
Credit: Catherine Powell

"It's really cool to partner with a brand that is just as avid in [giving back] and can tie in a fun element with live music," Morris continues. "People miss live music so much right now. To give them any bit of it is definitely a morale booster."

Maren Morris
Credit: Harper Smith

The star wanted to make sure her outfit was fit for a festival, so she plans on channeling one of Kate Hudson's most iconic characters on stage.

"I loved it because it's comfortable and it's crochet. It reminded me of Almost Famous vibes like Kate Hudson. So yeah, it's super cute and affordable. I love all those things," Morris says of her knitted design.

Maren Morris
Credit: Harper Smith

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The "Bones" singer always considers it a "win" anytime she gets "to play instruments and be with my band again." She also already has her setlist ready to go with some favorite hits included.

"I specifically chose three songs that I thought would work in a festival-y environment. Luckily they're old hat to me and my band at this point. Hopefully, you'll definitely get to sing along with [them]," she says.

Watch SHEIN Together Fest livestream on Sunday, May 2 (5 p.m. ET/2 p.m. PT) — only available via the SHEIN App.