Alabama and the Oak Ridge Boys have both reached the commercial safety of the middle of the country road, but the 'Bamans did it the easy way, not exactly clutching the Oaks' coattails but certainly studying their competitors' tailor-made suites. They are all solid citizens in Kenny Rogers' pop-country world, where melodies are often light, where harmonies are always earthy and appealing and where arrangements are inevitably air- tight.

"Mountain Music," which is the name of both Alabama's third album and its latest hit single, is a perfect distillation of the band's approach: a little Walter Brennan imitation intro, a lot of calculated naivete, random snapshots that evoke a honeyed postcard from the past ("Drift away like Tom Sawyer / Ride a raft with old Huck Finn / Take a nap like Rip van Winkle / Days dreamin' again"). Throw in a couple of bars of Civil War harmonica, a subdued slab of cajun fiddle, smooth harmonies and sharp production, and you have a hit single that's not confined to country stations.

The next step is to mix things up, show a little versatility: Alabama comes up with medium-tempo rockers ("Changes Comin' On" and "Lovin' You Is Killin' Me"), a lulling lullabye ("Never Be One"), a faithful oldies cover (Credence Clearwater's "Green River"), some dubious country-soul ("Take Me Down" and "You Turn Me On," the latter with a silly Barry White imitation), an Oaks-Rovers-style party song ("Gonna Have a Party") and even one old-fashioned tear- jerking country ballad ("Close Enough to Perfect"). It's all professional and easy to listen to, but there's nothing here as vibrant or heartfelt as "Feels So Right" or "Old Flame" from Alabama's last album.

y GAIL DAVIES, who's been denting the country singles charts since 1978, seems poised to break onto a higher level with her new album, "Givin' Herself Away." That title is deceiving, because Davies is one of the few women in country not only to write some of her own material, but also to arrange and produce her own albums. She's not overly adventurous, but she consciously avoids syrupy overprodution; in fact, the album has more of a light-rock touch, reflecting Davies' professional range over the last 10 years. More importantly, Davies has pulled together an album that is very pro-woman, not the soppy Nashville brand but the independent-thinker variety. She addresses a number of issues: the incautious balance between freedom and dependence, seen humorously in "Round the Clock Lovin' " and confusedly in "Movin' (I Might Decide to Stay)"; the pessimism brought about by bad experiences ("All the Fire Is Gone" and the title song) versus the optimism inherent in second chances (in a fine cover of Joni Mitchell's "You Turn Me On I'm a Radio"). One of two Davies originals, "It's Amazing What a Little Love Can Do" is a lovely, hopeful ballad in the Don Williams mold. With a strong voice that shines on two other covers (Marty Robbins' "Singing the Blues" and Roy Orbison's "Dream Baby"), Gail Davies seems ready to pop into the mainstream. Her independence and free spirit are sorely needed there. THE RECORDS, THE SHOWS THE ALBUMS ALABAMA, Mountain Music (RCA AHL1-4229). GAIL DAVIES, Givin' Herself Away (Warner Brothers BSK3636). THE CONCERTS ALABAMA, with Janie Fricke and three Washington country-rock groups, at Laurel Race Course, Saturday from 1 to 7. GAIL DAVIES, along with Loretta Lynn, Billy (Crash) Craddock, Dave Rowland and Sugar, Lee Greenwood, at the Country Jamboree at Bull Run Regional Park, Manassas, Sunday from 2 to 7. (Park opens at 10 a.m. for exhibits, crafts and games.)