Simpson is best known for his solo output as the Whistles & The Bells, his work as a founding member of Cadillac Sky, and the songs he has written for artists including Tim McGraw and Joe Nichols.
[1] As a songwriter, Simpson has written songs for Tim McGraw, Blake Shelton, Billy Currington, George Strait, Jason Aldean, and Joe Nichols,[2] whose track "Yeah" went to No.
Simpson has won NSAI's Country Awards Top 50 Songs for his work on Brad Martin's "Before I Knew Better", Tim McGraw's "Better Than I Used To Be", Blake Shelton's "I'll Just Hold On", and Joe Nichols' "Yeah.
[3] They recorded their debut album Blind Man Walking in 2006 for a January 2007 release on the Skaggs Family label.
Following his time in Cadillac Sky, Simpson began a solo musical venture in Nashville, called The Whistles & The Bells.