"Light On" is the first official single released from American Idol season 7 winner David Cook's major label debut studio album, David Cook. The single has been certified Platinum by the RIAA. "Light On" was co-written by Soundgarden and Audioslave front man Chris Cornell, as well as famed producer/songwriter Brian Howes. The song was produced by Grammy winning producer Rob Cavallo, who has produced hits for Green Day and Kid Rock.
"Light On" sold 109,000 digital downloads in its first week of availability, leading to a #17 debut on the Billboard Hot 100. It is Cook's second top twenty hit on the chart and second top forty hit. On 2/1/09 "Light On" reached #20 on Mainstream Top 40 radio, becoming Cook's first top twenty hit in that format. It has become his second consecutive top ten hit on the Adult Top 40, reaching #4. It has sold more than 1 million downloads in the U.S. to date. The single would later receive its RIAA Gold and Platinum certifications on January 20, 2010. In Canada it first debuted at #61 on the Canadian Hot 100 based on downloads, but then fell off the chart the next week. A few weeks later it made a re-entry on the chart, finally peaking at #27.
The music video for "Light On" was shot on October 21 and 22 at the Los Angeles Valley College football stadium with Wayne Isham as the director. On November 22, 2008, the video debuted at #1 on VH1's Top 20 Countdown.
Reception of "Light On" was generally positive to mixed. Billboard's Chuck Taylor gave a very favorable review saying "melodically, there's no question that this bullet is heading right for the brain, where the only thing stickier than the chorus is Cook's appreciably sweaty performance." He predicted success for Cook, stating "Like Chris Daughtry before him, here's an Idol who is bound for true rock cred", summing it up with "Light On" is right on."
Todd Martens of the Los Angeles Times gave a decent review, predicting chart success by saying the song was "sure to be inescapable this holiday season." He called it "full-on, cellphone-waving arena rock schmaltz, with husky, slow-moving guitars and a wallop of meaninglessly earnest vocals."
Michael Slezak of Entertainment Weekly also gave a mostly good review, saying Cook "is poised to be part of a balanced, mainstream rock diet alongside artists like 3 Doors Down, Nickelback, and Staind." He also called the song catchy saying, "After two listens, the "Light On" chorus got caught in my head like butter in the crannies of an English muffin." Though unimpressed with the song's lyrics, claiming they "feel more like a logjam of carefully focus-grouped words than anything deeply meaningful", he concluded however that "the bottom line is: "Light On" is probably going to be a major hit."
Ken Barnes of USA Today however was unimpressed with the single, despite being a fervent supporter of Cook on American Idol. Barnes called the song "Daughtry lite" as well as "a paint-by-numbers rock-ballad tune." Los Angeles Times writer Ann Powers also appeared unimpressed with the single, referring to it as a "banger in the worst sense of the word."