There’s some confusion regarding this theme song.
First, the facts. The theme is an original by W.G. “Snuffy” Walden, whom we have encountered in the themes for The West Wing and My So-Called Life among others. Some also credit Bennett Salvay (alongside) for the theme, but it is hard to confirm this for sure as there are discrepancies in sources.
The confusion is with regards to the Texas-based instrumental band Explosions in the Sky. Although their music was heavily featured in the film and in the series, and their eight-minute song “Your Hand in Mine” sounds awfully a lot like the theme, they had nothing to do with the opening tune (except maybe inspire). Even so, it is said that Mr. Walden took inspiration from Billy Joel’s music while he was still with the band Attila.
The theme song was released in the second official soundtrack of the show. It lasts 46 seconds (same as with opening sequence), and is officially titled as “Friday Night Lights Theme”.
Below is the official opening sequence for Friday Night Lights featuring the theme song.
Below is Explosions in the Sky’s “Your Hand in Mine”. See how the uploader even credited it as the “FNL theme song.”