Ace bass man Jimmie Lee Sloas has played metal, Christian pop, and myriad other genres, but he’s best known as bassist to the country stars. With his wide-ranging background, he can bring the bottom line to any track, whether he’s stoking the ominous fire of Carrie Underwood’s “Before He Cheats” with muscular, descending tones or punctuating the turns on the delicate country carousel of Kacey Musgraves’ “Merry Go ’Round.”