Omnivore's third and final installment of The Complete Capitol Singles of Buck Owens covers the years between 1971 and 1975 -- a time when Buck's overall stardom was at a peak thanks to Hee Haw but his grip on the country charts was beginning to loosen. These two developments were inextricably intertwined, a by-product of evolving from a Bakersfield renegade to a linchpin in the country showbiz establishment. As this was happening, the lineup of the Buckaroos began to shift, and by 1971, only Buck and his faithful lieutenant Don Rich were left from the iconic group that defined the sound and style of country music in the 1960s. Rich would soon die in a tragic motorcycle accident in 1974, but The Complete Capitol Singles: 1971-1975 makes it plain that Buck Owens had already started to drift creatively before his partner's death. Make no mistake, the double-disc set contains a lot of terrific music: he recasts "Bridge Over Troubled Water" so it's as quietly trippy as a Glen Campbell tune, the Buckaroos bluegrass album Ruby kicked up crackerjack A- and B-sides, Susan Raye proved to be an adept duet partner, "Made in Japan" (his last number one single, not counting Dwight Yoakam's 1988 cover of "Streets of Bakersfield") is a wry bit of Pan-Pacific country-pop, and country Halloween tunes don't come better than "(It's A) Monster Holiday." As good as it is, the latter does hint at how his era of Buck's is filled with novelties and cutesy slices of nostalgia. The worst of these are his vaudevillian duets with his son Buddy -- "Too Old to Cut the Mustard" and "Wham Bam" seemed designed for an off episode of Hee Haw -- but even some strong songs are plays on pop culture catchphrases ("You Ain't Gonna Have Ol' Buck to Kick Around No More," "Ain't It Amazing, Gracie"), underscoring how Buck spent the early '70s coasting on a wave created by other musicians. There's plenty of pleasure to be had in this -- Owens was still a sharp record-maker, after all -- but the seams are apparent throughout these two discs, evident in how Buck embraced the soft haze of AM radio and didn't always spend much time bothering with a memorable flip side. Even with these flaws, this Omnivore set is necessary for understanding this final act of Buck Owens' imperial years: by offering the duets and duds alongside the ace A-sides, it paints a full picture of Buck in twilight.