Red Oni, Blue Oni/Music


 * Microdisney were like this, with Cathal Coughlan being the red oni and Sean O Hagan being the blue oni. Their music was known for the contrast between Cathal's angry/melancholic lyrics and Sean's euphonic, peaceful melodies. This became even clearer when the band broke up due to a clash between the onis - Cathal wanted to make more aggressive music, Sean wanted to make softer music.
 * Space had Jamie Murphy and Tommy Scott as the respective oni. Jamie was a Fiery Redhead whose constant partying caused him to have a nervous breakdown, while Tommy was the more sensitive and introverted one of the two. The trope also applies in the musical sense as Tommy's songs were more melodious and romantic - albeit in a rather twisted way - while Jamie's were darker in tone, particularly on Spiders, and more indie rock-oriented.
 * During the heydey of Britpop, Oasis (the loud, outspoken, 70's rock and Beatles-influenced working class band) were the Red Oni and Blur (the quieter, witty, Kinks-influenced band consisting of University intellectuals) were the Blue Oni. Because of their respective Oni characteristics, Oasis were the more popular of the two, while Blur had more critical acclaim. The two bands also hated each other for most of the 90's, and so did their hardcore fans.
 * In The Who, Roger Daltrey was a more reserved, polite musician while Keith Moon was the Crazy Awesome drummer. They didn't always get along off-stage.
 * Aerosmith: Steven Tyler is the loudmouth, flamboyant frontman (Red) while Joe Perry is the quiet, mellow guitar player (Blue).
 * ABBA: playful and exuberant Anni-frid Lyngstad was the red oni, while discreet and reserved Agnetha Faltskog was the blue oni.
 * Sleater Kinney were an aural equivalent of this trope. Corin Tucker, whose voice was often harsh and abrasive, was the Red Oni. Carrie Brownstein, whose voice was generally much smoother and gentler, was the Blue Oni.
 * The Rolling Stones had Mick Jagger and Keith Richards.
 * The post-1999 Red Hot Chili Peppers had the loud and over the top Anthony Kiedis and the quiet, thoughtful John Frusciante, who got noticeably calmer and more reserved when he re-joined the band. Of course, his successor Josh Klinghoffer can fit the Blue Oni role as well.
 * In the band Rush, we have the goofy, playful guitarist, Alex, who is most definitely the Red Oni to quiet, shy, bookish drummer Neil's Blue Oni. Interestingly, Alex's Heterosexual Life Partner and childhood friend, the bassist/vocalist/keyboardist Geddy, is a Purple Oni- he's soft-spoken and quiet, but more approachable and personable than Neil, who often doesn't show up for interviews, meet-and-greets, or special events because he's just not good with people.