Madilyn Bailey Wold, commonly known as Madilyn Bailey and Madilyn, is an American singer, songwriter, musician, and YouTube personality. She has appeared on multiple TV live shows in France to promote her cover singles and she also promoted her original single "Tetris" on the American TV show Today in 2018. As of February 2024, she has about 9.6 million subscribers on YouTube.

"Titanium" is a song by French DJ and record producer David Guetta, featuring vocals by Australian singer and songwriter Sia. Taken from Guetta's fifth studio album, Nothing but the Beat, the song was written by Sia, David Guetta, Giorgio Tuinfort and Afrojack. Production was also handled by Guetta, Tuinfort and Afrojack. "Titanium" was initially released for digital download on 25 August 2011, as the first of four promotional singles from the album. It was later released as the album's fourth single in 2011. The song originally featured the vocals of American recording artist Mary J. Blige, whose version of the song leaked online in 2011.