Former First Lady Michelle Obama took a brief break from her blockbuster book tour on Sunday night for a surprise appearance at the start of the 2019 Grammys.

Obama, 55, appeared onstage alongside Grammys host Alicia Keys and Lady Gaga, Jada Pinkett Smith and Jennifer Lopez to discuss the important role music had played in their lives.

Introducing the segment, Keys said, “Music is what we all love, music is what it’s all about. Everybody is out here shining and I’m so proud to bring us together to honor this moment because music is what we cry to, it’s what we march to, it’s what we rock to, it’s what we make love to. It’s our shared global language.”

A source familiar with the planning tells PEOPLE Obama attended for Keys, a friend.

Keys had been to the Obama White House a couple of times, says the source.

“It’s a nice friendship that they have,” the source says. “Mrs. Obama just wanted to be supportive of Alicia.”

At the show on Sunday night, after Gaga, Lopez and Smith each spoke, Obama delivered a brief speech to audibly rapturous reaction.

“From the Motown records I wore out on the South Side to the ‘who run the world’ songs that fueled me through this last decade, music has always helped me tell my story, and I know that’s true for everybody here,” Obama said.

Be sure to check out PEOPLE’s full Grammys coverage to get the latest news on music’s biggest night.

She continued: “Whether we like country or rap or rock, music helps us share ourselves, our dignity and sorrows, our hopes and joys. It allows us to hear one another, to invite each other in. Music shows us that all of it matters — every story within every voice, every note within every song. Is that right ladies?”

Keys then took a second to “soak in” the assembled group. She playfully noted, referring to the Beyoncé song, “Who run the world?”

On Twitter, Obama posted a behind-the-scenes photo of the five-some and gushed about Keys.

“A big part of friendship is showing up for your girls—that’s why I was thrilled to be there for the one and only @aliciakeys at the #GRAMMYs,” she wrote, adding, “[Keys] is one of the most genuine and thoughtful people I know—there’s no one better to help us all celebrate the unifying power of music!”

Be sure to check out PEOPLE’s full Grammys coverage to get the latest news on music’s biggest night.

Keys, 38, was announced as Grammys host last month.

“I’m soooo EXCITED,” she said at the time. “There’s so much in store and I CAN’T WAIT for y’all to see it ALL come to life.”

“I know what it feels like to be on that stage and I know what it feels like to be proud of the work that you’ve put in, and to be recognized for it. And I just feel grateful that I’m able to bring that light and that energy,” she said in the video. “This is a first. It’s a first. It’s amazing. And I think it’s perfect timing. Honestly, I’m really excited. I feel really good about it, because I feel like it’s the perfect opportunity to give the light back [and] to lift people up, especially all the young women who are nominated. To me, it feels like sister vibes.”

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Last week Keys appeared on The Late Late Show with James Corden for some playful tips from the show’s most recent host — in the form of a parody of “Shallow,” the signature song from A Star Is Born.

Sample line from Corden to Keyes: “Try not to be scared / Act like you’ve been there.” And: “After four hours you’ll find yourself drinking cheap booze.”

Obama, meanwhile, has been touring the country to sold-out venues in support of her memoir Becoming, which has sold millions of copies since its fall release.

RELATED: Alicia Keys Parodies A Star Is Born‘s ‘Shallow’ with James Corden to Prep for Grammys

Becoming is a candid account of her life, marriage to former President Barack Obama and their time together in the White House.

In an at-home interview with PEOPLE, Mrs. Obama talked about the value of being so open — and about her and her husband seeking counseling for their relationship, revered by so many.

“Because we’re role models, it’s important for us to be honest and say, ‘If you’re in a marriage and there are times you want to leave, that’s normal,’ because I felt that way,” she said.

The 61st Annual Grammy Awards are broadcasting live from the Staples Center in Los Angeles on Sunday, Feb. 10, at 8 p.m. ET/5 p.m. PT on CBS.