Pittsburgh-bred rapper Wiz Khalifa's 2011 album, Rolling Papers, took the buzz that had been building around his early tracks and mixtapes and pushed him into the realm of stardom.

The album included the breakthrough smash hit "Black & Yellow," but instead of simply packaging a summer banger with extraneous filler, the entire thing was strong and consistent, introducing the world to Khalifa's stoned charisma and smoky sound that felt exciting and raw while maintaining a decidedly mainstream pop friendliness.

The years that followed saw Khalifa moving even higher up the ranks with his approachable productions and weed-obsessed flows, perhaps peaking in terms of visibility with "See You Again," a 2015 duet with Charlie Puth from the Furious 7 soundtrack.

It doesn't get much more mainstream than a number one hit from a summer blockbuster, but while Khalifa's soundtrack appearances were topping the charts, he was busy behind the scenes working on the long-labored Rolling Papers 2, a follow-up to his 2011 breakthrough that turned out to be far darker and less commercial than his worldwide hits.

When the album finally arrived in the summer of 2018, after over three years of studio construction, it boasted an epic list of collaborators and a 25-song track list over an almost 90-minute running time.

Eerie singles like "Real Rich" featuring Gucci Mane set the tone for Rolling Papers 2, a lengthy and often murky slow-burner that found Wiz drifting through midtempo trap beats, humid R&B-tinged songs, and the kind of too-high-to-die delivery that defined his style from the start.

The mostly laid-back affair sometimes amps up, especially on the unyielding trap burner "Blue Hunnids" featuring guest spots from Hardo and late Pittsburgh MC Jimmy Wopo.

Other standouts from Rolling Papers 2's long list of contributors include R&B duo THEMXXNLIGHT, who add sultry vocal hooks to three songs including the Drake-reminiscent "All of a Sudden," as well as guest rappers from Snoop Dogg to Ty Dolla $ign and even an appearance from old-school legends Bone Thugs-N-Harmony on "Reach for the Stars." The production on some songs from Curren$y connects with the bloodshot charm that made Khalifa a star to begin with, but even the long list of guest stars can't rise above the tedium that starts setting in before the midway point on this overly long and ultimately impenetrable album.

Though there are highlights, the majority of Rolling Papers 2 is repetitive filler, uninspired with overly similar beats backing rhymes from Wiz that feel absently recited.

Instead of a magnum opus from an artist reaching the next level of his craft, or even a serviceable new album, Rolling Papers 2 feels like an awkward mixtape (or two) without much to say and too stoned to realize it's been rambling.