Louise, 28, has not exactly been laboring in big sister Barbara's shadow, having recorded such duet hits as Reunited with her husband, R.C. Bannon. This, however, is her first solo album. (It's more like half an album, actually, containing only six songs. It's part of a new RCA experiment, in which people will get less music for less money—a suggested retail of $6.98. If this eliminates part of the stupefying padding that goes on with some albums, it might be a worthwhile idea.) She sings her solo hit, Some of My Best Friends Are Old Songs, as well as This Bed's Not Big Enough and Save Me, which was written by Bannon, Guy Fletcher and Doug Flett. Mandrell's singing is from the hard-edged Nashville school, relentless and full of zip—and sometimes about as subtle as a plow.