Tim McGraw can add a few new milestones to his already stellar career. Last week, he chalked his 30th No. 1 song with 'Nine Lives,' the first single from Def Leppard's latest CD, 'Songs From The Sparkle.' The collaboration also makes him the first country artist in history to reach No. 1 on Billboard's Classic Rock chart, as well as the first country artist to appear on the Active Rock Chart. The song, which features a guest vocal from McGraw, was co-written with McGraw and Def Leppard bandmates Phil Collen, Joe Elliot, and Rick Savage.

The collaboration was McGraw's idea three years ago, before he even met the band. His tour manager, Robert Allen, is the brother of Def Leppard's drummer Rick Allen. The country star finally met the rockers at the Hollywood Bowl in 2006.

This isn't McGraw's first time on a chart of another genre. His 2005 duet with rapper Nelly, 'Over and Over,' stayed at the top of Billboard's Mainstream Top 40 chart for 12 weeks. That song also marked the first time a country artist appeared on Billboard's Hip-Hop/Rap Singles Chart.