You probably know Gavin DeGraw for his music, which has been featured on shows like House, One Tree Hill, and even The Bachelor. For years, the country singer has been a household name—and Grammy-winner Colbie Caillat has a similarly impressive resume. The pop songstress and songwriter cut her teeth writing for Taylor Swift before graduating to a solo career, which the hit 2009 record Breakthrough.

Ordinarily, tickets to see a pair like this perform would cost a pretty penny. But Milkshake has a way you can get in for free.

Colbie and Gavin have teamed up with Tickets-for-Charity, an organization that makes every song count. The way it works is simple: If you buy tickets for a show through Tickets-for-Charity.com, a portion of the funds are automatically donated to causes chosen by the artist (and the customer). For their 2012 tour, Gavin and Colbie have chosen to support The Humane Society, The GRAMMY Foundation, and the VH1 Save the Music Foundation. Colbie has been a longtime supporter of the Humane Society and led a campaign last year with the HSUS to fight puppy mills. Gavin is a Labels for Education Artist Ambassador for the GRAMMY Foundation, and both are VH1 Save the Music Ambassadors.

Want to see two of your favorite stars stretch their pipes totally for free? Tickets-for-Charity is giving away a pair of tickets to one lucky Milkshake reader. The tickets are good for any date on their 2012 tour, but here's the best part: They include a meet-and-greet with either Gavin or Colbie!

Click here to enter this very special giveaway. To learn more about Tickets-for-Charity—or to purchase tickets for this tour—go to Tickets-for-Charity.com. And just in case one of these causes isn't particularly close to your heart, Tickets-for-Charity also lets the customer choose where their donation goes.