Though it might be frustrating for music collectors to replace outmoded editions of their favorite albums, it's hard to find fault in the glut of CD reissues in the '90s. After all, if a disc can handle over an hour of information, it only makes sense to repackage older albums with bonus tracks, B-sides, alternate takes, and whatnot. But as gratifying as many collectors' editions have been, it's easy to forget just how much music has been overlooked or given short shrift by CDs. Soul artists, for example, used to churn out albums at an alarming rate, and while there was a lot of filler, it would be nice to know that the complete recordings of James Brown or Sam Cooke are out there somewhere. Perhaps no genre suffers more from this phenomenon than country music, which has rarely received the sort of lovingly serious treatment afforded rock and other genres. With any luck, Columbia's new "American Milestones" serieswhich in these initial releases repackages, remasters, and adds bonus tracks to five stylistically diverse country albumsindicates a change in direction. Perhaps the most significant is the new version of Johnny Cash At Folsom Prison. Already a strong contender for the best live album ever, Folsom features Cash, who knows a thing or two about run-ins with the law, singing songs about prison, crime, death, and redemption to an understandably receptive audience. The Shel Silverstein-penned death-row anthem "25 Minutes To Go" might sound like a funny novelty song in another setting, but here it sounds like black comedy at its most extreme. This new version of Folsom not only includes the complete concert, including three previously discarded tracks, but also removes the puritanical bleeps, in case you want to hear Cash swear. In addition to featuring her signature song, Tammy Wynette's Stand By Your Man provides an excellent example of the lush Billy Sherrill sound that dominated country in the late '60s and early '70s. The album also provides a fuller portrait of Wynette's musical talent and personal politics than that one unmistakable song suggests. Those who take objection to Wynette's man-standing will find a more complicated vision on the album as a whole. The genre-jumping Marty Robbins scored one of his biggest hits, and an early country-western crossover success, with 1959's Gunfighter Ballads And Trail Songs, a fine selection of Western-themed numbers that includes the enduring "El Paso." Aside from the inclusion of a few hits ("I Always Get Lucky With You," the title track), Merle Haggard's Big City, his 47th album, seems to have been chosen more because it was his first for Epic than for any sort of thematic unity. A solid if unextraordinary record, it does, however, include one of his most hilarious the-world-is-going-to-hell laments in the form of "Are The Good Times Really Over (I Wish A Buck Was Still Silver)," in which Haggard lays the blame for America's decline on, among other things, The Beatles, microwaves, and the inability to find an American car that lasts 10 years. There's no ignoring the conceptual unity of Willie Nelson's Stardust, a 1977 album as daring as anything he's done. At the risk of alienating his core audience, Nelson turned in a set of standards from the songbooks of Gershwin, Berlin, Carmichael, and others. Nelson might not have been anyone's first choice to interpret "Moonlight In Vermont" or "All Of Me," but paired with the unlikely production talents of Booker T. Jones, he does a fine job, creating an enduring testimony to the value of country music as an album art.