'The Hills' Musical Legacy: Natasha Bedingfield, Lady Gaga And More

Artists from Hilary Duff to Journey owe a debt to 'Laguna Beach' and its spin-off.

Tuesday night (July 13) represents a huge moment in the history of MTV programming and reality television in general. After six seasons, "The Hills" is coming to a close with a two-hour grand-finale event, beginning at 8 p.m. on MTV. It has been a watershed program, as it first established the sort of hyper-real aesthetic that many reality shows (and a handful of fictional dramas) copied. But "The Hills" and its predecessor, "Laguna Beach," also left their mark in the music world.

Each of the shows had theme songs that helped spark massive career moves for the artists behind them. The theme song to "Laguna Beach" was Hilary Duff's "Come Clean," co-written by Kara DioGuardi and John Shanks. Though it originally appeared on Duff's 2003 album, Metamorphosis, and was released as a single in early 2004, it really picked up steam once it accompanied the premiere of "Laguna Beach" in September of that year. It peaked at #9 on the Billboard Pop Songs chart and earned Duff a shortlist recommendation (though no actual nomination) for Best Female Pop Vocal Performance at the Grammy Awards.

"The Hills" theme song did even better by its artist. When Natasha Bedingfield's "Unwritten" debuted as the tune that introduced the world to "The Hills" in May 2006, it stormed up the Billboard Hot 100, peaking at #5. In fact, because of its crossover appeal, "Unwritten" became the most-played song on the radio in the United States in 2006. Not bad for a track that was originally released in 2004 on Bedingfield's debut album of the same name.

"The Hills" also gave the world some early exposure to Lady Gaga. Before Gaga's debut album, The Fame, took over the airwaves, she performed at a fashion show where Conrad and friend Whitney Port styled her. Gaga was even the subject of a minor plot in that episode, as the zipper of her catsuit broke, forcing Conrad to repair it and save the day.

But perhaps the most lasting musical legacy of "The Hills" is actually a moment from "Laguna Beach." The second-season premiere of "Laguna Beach" (which aired in July 2005) featured a scene wherein castmember Stephen Colletti picks Conrad up for a date. The song playing in Stephen's car during the scene? Journey's "Don't Stop Believin'," which had yet to receive its second renaissance thanks to the series finale of "The Sopranos" (which didn't air until two years later). Exposure on "Laguna Beach" (along with its appearance on a "Family Guy" episode the same week) sent the track skyrocketing into the iTunes Top 10, an amazing feat for a song that was nearly 25 years old.

What was your favorite musical moment from "Laguna Beach" and "The Hills"? Let us know in the comments!

Join MTVNews.com on Tuesday, July 13, at 8 p.m. ET for a live stream from the red carpet of Hollywood's Roosevelt Hotel, where the stars will gather for "The Hills Live: A Hollywood Ending." Then tune in for the series finale at 10 p.m. ET on MTV and "The Hills Live: A Hollywood Ending After Show" at 11.