There are at least 5 artists with this name:
1) I is a Norwegian supergroup that plays heavy metal with black metal influences. The band contains members from other black metal bands, Immortal (Abbath,Demonaz and Armagedda), Gorgoroth (TC King), and Enslaved (Arve Isdal). According to the official website of the band, one of their major influences is the band Bathory.

The band's debut album, Between Two Worlds, was released on November 3, 2006 in the United Kingdom and November 14, 2006 in the United States through Nuclear Blast Records. Their first and only live show was at the "Hole In The Sky" festival in Bergen, Norway on August 26, 2006. Currently there are no more scheduled live shows.

2) I, is also a post-UrbanDepressive band from Braga, Portugal.(http://www.myspace.com/ipud)

3) German electronic musician Uwe Schmidt, most known as Atom Heart.

Discography:
1992 - Percussion Overdose (12",Pod Communication)
1992 - Repetitive Digital Noise (CD,Pod Communication)
1992 - Warm Sunday (12",Pod Communication)
1994 - Tinned Music (CD,Pod Communication)
1996 - Tinned Music (2xLP,Pod Communication)
2006 - Repetitive Digital Noise (12",Recognition)

4) German old school hardcore Band from south Germany

5)A Side project by several current and stepped-out Walkabouts members. Stricktly instrumental and experimental.

6) Cha Yoon-ji (Hangul: 차윤지; born December 2, 1996), better known by her stage name I, is a South Korean singer and dancer under WM Entertainment. She officially debuted on January 12, 2017 with her debut EP I Dream.
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Artist biography from last.fm