Although many music journalists have been declaring/celebrating the death of “bro-country” for the past year or so, artists such as Florida Georgia Line, Luke Bryan and Thomas Rhett continue to fill country charts and airwaves with plenty of trucks, bonfires and the like.

However, with the successes of Chris Stapleton and Kasey Musgraves, a more mature and less polished brand of country music has shown that it can compete with bro country. The divide between the two is comparable to rock music in the early 90s, with this new wave of outsiders playing the grunge to bro country’s hair metal.

One of the most fascinating artists of this movement is one Sturgill Simpson. The Kentucky-born songwriter’s first album, 2013’s “High Top Mountain,” was an excellent piece of traditional country music, with Simpson’s vocals and musical style comparable to Waylon Jennings.

The next year, Simpson displayed his experimental side on Metamodern Sounds in Country Music, which reached the eleventh spot on the Top Country Albums Chart. With his new album, “A Sailor’s Guide to Earth,” Simpson seems to turn further away from a traditional country sound and delves into R&B, blues and even orchestral elements.

The first track, “Welcome to Earth (Pollywog),” greets the listener with the lines “Hello, my son/ Welcome to Earth.” The song’s lyrics refer to his relationship with his newborn son and the music builds like an epic film score.

The brilliantly heartbreaking “Breakers Roar” is musically one of the most familiar tracks on the album. It could have been featured on “Metamodern Sounds” and fit in perfectly. “Sea Stories” fits well with the nautical theme of the album and is probably the album’s most country-sounding track.

One of the album’s biggest selling points is Simpson’s cover of Nirvana’s classic, “In Bloom.” Simpson turns the seminal grunge hit into a beautiful, slow-burning, psychedelic ballad.

The music-box effects, steel guitars and Simpson’s small lyrical alteration (changing “and I say yeah” into “to love someone”) turn Cobain’s sarcasm into something more emotional and earnest. The “In Bloom” cover is followed by the strongest song on the album, “Brace for Impact (Live a Little).”

Simpson’s vocals and melodies are impeccable as the band grinds out an infectious bluesy groove. The lyrics are simple, yet effective — “We’re dying to live, living to die/ No matter what you believe.” While most of “A Sailor’s Guide to Earth” is relatively laid-back, it closes out with a barn-burner, “Call to Arms,” that echoes the best of Chuck Berry and honky-tonk music.

While not as country-sounding as his previous two releases, Simpson’s soulful twangy voice is still present, as are the haunting steel guitars and wonderful musicianship. With “A Sailor’s Guide to Earth,” Sturgill Simpson has shown that he is more than simply a talented country songwriter. He has the potential to be a major force in music, even if bro country stays around forever.