by Mark Deming 　　In 1975, Merle Haggard was enjoying his biggest crossover hit since "Okie from Muskogee" when he wrote and performed the theme song for the television series Movin' On (which starred Claude Akins and Frank Converse as a pair of gypsy truck drivers), and it's no surprise that the song became the title track to one of the two albums Hag released that year. Despite its chart status, "Movin' On" was one of Haggard's less impressive celebrations of the working class, and with the exception of a high-spirited cover of Dolly Parton's "Kentucky Gambler," the bulk of this set is dominated by love songs. If the arrangements and production are noticeably more tricked up than the minimal perfection of Haggard's 1960s sides and these lyrics aren't his sharpest meditations on the male/female relationship, for the most part Keep Movin' On finds Hag in worthy form, and "Always Wanting You," "A Man's Got to Give Up a Lot," and "September in Miami" are memorable if lesser-known numbers. In short, anyone who loves Merle Haggard's music won't be let down by picking this up, and while this is hardly the place to start investigating his albums for Capitol, it's still a notch or two above his average, if not a masterpiece.