"It's a humbling experience to have a generation of kids -- some weren't born when the original came out -- [listen] to the song now and creating their own feeling toward it," Monica, 34, said in a phone interview Monday.
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"So Gone" became a No. 1 hit on Billboard's Hot R&B/Hip-Hop Songs chart and peaked at No. 10 on the Billboard Hot 100 in 2003. After selling a few hundred copies in recent weeks, the song jumped from 224 digital sales to 2,080 through Aug. 12-18, according to Nielsen Music. The single had an 829 percent increase in download sales in the week ending Aug. 18, rising from a negligible figure sold in the week previous to a little over 2,000 sold. Total on-demand streams of the song (both for its audio and video) grew 289 percent for the week, climbing from 235,000 to 917,000.
And Spotify said there's been about a 140 percent increase in streams for "So Gone" since Aug. 11.
Fans have launched both serious and hilarious videos for the challenge, from wedding proposals to playful fights about sharing boyfriends. Monica said she was inspired to take on the challenge after watching Chance show love to his future baby's mother.
She said Elliott called her about how the #SoGoneChallenge had gone viral and later helped her craft her rhymes in the studio.
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"I told her I wanted to take a moment and say, 'The same girl that I used to be, I'm her still, I just grew. I grew as a person,'" said Monica, who posted her version last week and earned praise for her lyrics.
Monica said "So Gone," a song about a man's infidelity that samples The Whispers' 1977 tune "You Are Number One," was based on a phone conversation she had with Elliott. It was featured on her third album, After the Storm.
The album was created after Monica dealt with the suicide of her boyfriend and the deaths of her grandmother and cousin. She remembers feeling inspired and recharged when she recorded "So Gone."
"'So Gone' is a record that's really special to me and always has been," she said. "My real hope is that ... it does make somebody feel like how I felt when I was making it. I felt hopeful, I was refocused, and I was realizing that my test would eventually be my testimony and that I was here for a reason."
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She said it's special to share this moment with Elliott, who has produced other songs for her, including the No. 1 R&B hit "Everything to Me."
Monica said they were working on new music the day she filmed her #SoGoneChallenge video, which showed Elliott in the background.
"This definitely sparked something special and ... as soon as we create a record that feels like ['So Gone'], I'm going to put it out," she said.