From Wikipedia

Jimmy Buffett's License to Chill is a collection of some of the singer/songwriter's favorite songs. The man who routinely packs arenas with tens of thousands of merry revelers occasionally slips unannounced into bars to play. And when he does, he draws from a different repertoire than "Margaritaville" and the rest of the songs that have made him so famous.

On this album, Buffett has many duets with noted contemporary country music artists, on country songs including “Hey Good Lookin’" by Hank Williams. This rendition reached No. 8 on the Billboard country singles charts; another single, ”Trip Around the Sun" (a duet with Martina McBride) reached No. 20. A third single, a solo version of "Piece of Work", was released in early 2005.

The album features the most covers he's recorded for an album – 11 of the 16 songs are covers. It sold 238,600 copies in its first week of release according to Nielson SoundScan and became his only album to reach No. 1 on the Billboard 200 album chart.