Robin Everhart, the Rival Sons' founding bassist, left in late October of 2013, deciding that the grueling rigors of touring weren't for him.

The band replaced him with Dave Beste in time to record the band's fourth full-length.

Once more they enlisted producer Dave Cobb (who helmed the Head Down sessions) and recorded at his Nashville studio.

Rival Sons have doubled down on their worship of late-'60s psych, blues-rock, and hard rock because of the lockdown groove in drummer Michael Miley's interplay with Beste, a much more straight-ahead rock bassist.

What's different is how the band combines these sounds, Led Zeppelin's pervasive guitar and vocal influence still a primary inspiration, but this is colored also by a love the Jimmy Page-era Yardbirds, the Nazz, the Doors, and the boogie of classic Status Quo.

The group has manifested most of these before, but not in this way.

In their songwriting and arrangements, they recombine these influences in sometimes startling new ways.

Even the most sprawling, psych-oriented tracks have excellent riffs, while most of the hard rockers and boogies contain hooks and multiple textures.

Force is never sacrificed.

Opening single "Electric Man" is unabashed in its Led Zeppelin IV proclivities, but "Good Things" evokes the Zombies of Odessey and Oracle with harder-edged guitars and fatter drums.

"Secret," led by Beste's bass throb and Scott Holiday's thundering guitar vamp, makes room for guest keyboardist Ikey Owens (Mars Volta) on organ.

"Open My Eyes" opens with a vamp worthy of Black Sabbath, but it becomes a gritty, near country-rocker with phased drum kit.

The transcendent Pete Townshend-esque guitar chords that serve as the intro to "Belle Starr" give way to a crunchy slide riff, then an open, spacious psychedelia.

It changes shape several times before the close with a woolly, dirty-assed bassline and Zep-style rhythmic syncopations.

The proggy blues in the intro to "Destination on Course" is a fine showcase for Jay Buchanan's croon atop brooding guitars and a swelling menace in the rhythm section.

This holds sway until a female backing chorus (Kristen Rogers) enters, and things come completely off the rails in Wagnerian mind-melting psych.

Great Western Valkyrie continues to revel in retro-rock, but it does so with fine songwriting, arrangements, and -- above all -- taste added to the instrumental firepower.

Combined, these strengths make this a full step up from Head Down.