Zakk Wylde, the leader of Black Label Society, is known for his burly physique, gruff voice, self-deprecating personality and insatiable love for the Yankees. He's dead serious, though, when it comes to his guitar and his music. For the band's cover of Bill Withers' 'Ain't No Sunshine When She's Gone,' the beefy guitarist showed off his softer, gentler and more thoughtful side.

It's a welcome and emotional change of pace. Even rockers have hearts! This is Zakk's heart, 'Unblackened.'

With a mournful guitar tone and Wylde's pain-drenched vocals, where he sounds as though he is channeling heartache from the deepest recesses of his heart, the song is impactful and lets us have a peek at Wylde's emotional core. Sonically, it has a classic rock vibe.

"'Ain't No Sunshine' is such a beautiful, heartfelt song. I've always loved it and wanted to cover it," the singer and guitarist said about the choice to tackle this particular track. "It felt so right in the context of [our live album]."

BLS will issue their double live album 'Unblackened' on Sept. 24 in multiple configurations. It will feature 'Ain't No Sunshine When She's Gone.' Take a listen to the track via Rolling Stone.