Of a Revolution, better known as O.A.R., is an American rock band consisting of Marc Roberge (vocals, guitar), Chris Culos (drums, percussion), Richard On (guitar, backing vocals), Benj Gershman (bass guitar), and Jerry DePizzo (saxophone, guitar, backing vocals). Due to massive online distribution over campus networks, the band has become a hit among college students, with many songs relating to the band members' personal lives at The Ohio State University and growing up in Rockville, Maryland.

The band was founded in 1996 by Marc Roberge and Chris Culos, inspired in part by Roberge's older brother who plays drums for the band Foxtrot Zulu. They then recruited Richard On and Benj Gershman. In 1997 they recorded "The Wanderer" at Gizmo Recording Company in Silver Spring, Maryland with engineer/producer Gantt Kushner. The four of them graduated from Wootton High School in Rockville, Maryland, then moved to Columbus, Ohio to attend the Ohio State University. While at Ohio State, they met Jerry DePizzo, from Youngstown, Ohio. In 2000 they returned to Gizmo Recording to record "Souls Aflame".

Without any formal marketing or advertising plans, news of their songs such as "That Was a Crazy Game of Poker", "City on Down" and "Night Shift" spread by word of mouth alone. Over the years, the band played as many shows as they could, expanding from the fraternities and sororities of Ohio State to any audiences that cared to listen. This exposure paid off; their third album Risen debuted at #11 on the Billboard top internet sales chart. The following year, their fourth album Any Time Now debuted at #156 on the Billboard 200 chart. They received offers from various major labels, but signed with Lava Records because they promised not to change the band.

In 2005, O.A.R. released their fifth album, Stories of a Stranger, which debuted at #40 on the Billboard 200. It produced the singles "Love and Memories", "Heard the World", and "Lay Down". "Love and Memories" was the band's first single to chart and receive significant radio airplay, peaking at 98 in the Pop 100, at 30 in Modern Rock Tracks, and at 18 in Adult Top 40. The music videos for "Love and Memories" and "Lay Down" also received airplay on VH1 and MTV. The video for "Lay Down" also received a "Woodie" award from MTV for streaming video.

On January 14, 2006, O.A.R. reached a new peak of popularity by drawing roughly 18,000 fans and selling out New York City's Madison Square Garden, which earned them a review in the New York Times. On October 5, 2006, a press release declared that O.A.R. had officially sold in excess of 1.2 million albums over their career. The band attributes much of its popularity to the taping and subsequent trading and downloading of their live shows.

On July 15, 2008, O.A.R. released their sixth studio album, All Sides. The first radio single for All Sides, "Shattered (Turn the Car Around)", was released for download on June 13. It surpassed "Love And Memories", peaking at 2 in Adult Top 40. In December 2008, VH1 named the music video for "Shattered" as number 18 on their Top 40 Videos of 2008.

The band released a new live album (Rain or Shine) on January 12th, 2010. The band has also hinted at a new studio album being ready in the summer of 2010. The album is being produced by Matt Wallace, who also produced All Sides.