Mastodon have a catalog of heavy albums, their latest being 2017’s “Emperor of Sand,” and all of them are ripe with heavy, murky guitar riffs, pummeling rhythms deep and dark lyrical themes.

When it comes to the meanings behind Mastodon’s songs, it’s a bit secretive. That’s on purpose.

“Our lyrics are open to interpretation by the listener,” Mastodon guitarist Bill Kelliher told Alternative Fix during an interview about the band’s “One More ‘Round the Sun’ release.

“You can find something in the lyrics that speak to you directly,” he added. “But, we always add elements of loss and death and people passing, and there’s a lot of sadness in there.”

More than anything, Kelliher says creating Mastodon albums is cathartic.

“Basically, ‘Once more ‘Round the Sun’ means it’s another year in the life of our band and the crazy internal things that are happening with us,” he said.

“There have been a lot of changes and crazy people that have entered our lives and left our lives, and that’s the concept,” he added.

Mastodon are currently touring the U.S. The band is slated to appear at Louder than Life festival in Louisville, Kentucky, this weekend.