Duets, an album released on the eve of Ronnie Milsap's 76th birthday, kicks off with something unexpected: a heavy, clanking blues stomp assisted by ZZ Top's Billy Gibbons, who is only too happy to salute "Southern Boys and Detroit Wheels" with the country singer. The pairing may be slightly unexpected -- Milsap is pure honey, Gibbons a hard patch of gravel -- and the song may not be well-known, but that's what gives the cut a kick that's not often heard elsewhere on Duets. Frequently throughout the album, Milsap and his partners favor the smooth and familiar, playing such big hits as "Stranger in My House," "Happy Happy Birthday," "Lost in the Fifties," or "Smokey Mountain Rain." The latter is distinguished by a game appearance by Dolly Parton, who hits the sweet spot between crowd-pleasing and interpretation. Kacey Musgraves hits that too with "No Getting Over Me" -- hearing her on this simmering, soulful piece of country-pop, it's clear that Golden Hour is indebted to the golden era of yacht-country -- but a lot of the other highlights find Milsap connecting with straight roots of some sort: singing hardcore country with George Strait on "Houston Solution," skipping through the twilight with Willie Nelson on a "A Woman's Love," and getting down and dirty with Leon Russell on "Misery Loves Company." The presence of Russell suggests many of the cuts on Duets may have been sitting around for a while -- he died in 2016, a little over two years prior to this release -- but that doesn't affect how the album plays. Listened to as a whole, without sweating the sources, Duets is an amiable, enjoyable testament to the many different facets of Ronnie Milsap.