During the public memorial held inside Los Angeles' Staples Center on Monday, the singer sweetly performed a song on the piano that held a very special meaning to the late NBA star and his wife, Vanessa Bryant.
Dressed in purple, Keys performed Beethoven's "Moonlight Sonata" on a purple piano. It's a song Bryant once learned to play, by ear, for his wife of 20 years.
Matt Barnes spoke to ET earlier this month about learning of his former teammate's hidden talent of playing the piano while they were traveling with the Lakers.
"There's always big grand pianos in all the hotels we stay in. And one time, he sat down and started playing a little bit," Barnes recalled. "Maybe two or three weeks later -- I don't remember where we were at but we were in another hotel lobby -- and he starts playing this familiar tune. I'm like, 'I know this tune, who is it?' And the security is like, 'It's Beethoven.' I'm like, 'What?' He's like, 'Yeah, he taught himself Beethoven in like two weeks. I'm like, 'What the hell? Are you kidding me?'"
"He was playing the piano like it was nothing," Barnes added. "It was just incredible to me that when he locked in on something, there were no barriers. He tapped into that other side of the brain that people don't get a chance to use. He knew how to get to that other side."
Bryant and his daughter, Gianna, died on Jan. 26, just a few hours before the 62nd Annual Grammy Awards kicked off inside Staples Center, the arena famously known as "the house that Kobe built." Keys hosted the event and began the ceremony with a few words honoring the NBA legend.
"Here we are together on music's biggest night, celebrating the artists that do it best. But to be honest with you, we're all feeling crazy sadness right now, because earlier today, Los Angeles, America and the whole wide world lost a hero. And we're literally standing here heartbroken in the house that Kobe Bryant built," she said. "Right now, Kobe and his daughter, Gianna, and all of those that have been tragically lost today, they're in our spirit... our prayers. They're in this building. And I would like to ask everyone to take a moment and hold them inside of you and share our strength and our support with their families."
"We're going to sing together... we're going to cry together," she added. "We're going to make sure that we are celebrating the most powerful energy, the most beautiful thing in the entire world... music."
Following the show, Keys opened up to ET backstage about how she managed to get through hosting the emotional night.
"This was a really hard night, and that's why I think it was a roller coaster," she shared. "It was painful, it's painful right now. We lost a beloved, beloved hero to all of us. A person who is like a true example of brilliance and excellence."
"It's not easy to go forward with all of that weight," she added. "But I think that the energy that he always brought and that fighting spirit... is what brought us through tonight."
Hear more in the video below.