Emmylou Harris has been around since the 1970s, when she emerged as a very big deal on the country-music scene. Her first major-label album, Pieces of the Sky, was released in 1975; her second, Elite Hotel, later in the same year. She went on to an amazing run between then and the revered 1980 bluegrass-acoustic Roses in the Snow. These early albums feel fresh and unspoiled nearly five decades on.

I don't think Harris has cut a bad or mediocre recording since then, but most listeners will agree, I believe, that these constituted her peak years, when she was a country star like no other. Her country was a sui generis form, at once intensely traditional and thrillingly innovative, based as much in folk and pop as in the Grand Ole Opry. It was also as soulful as it was intelligent. She championed roots-oriented songwriters such as Rodney Crowell, Gram Parsons, Townes Van Zandt, Steve Earle and Jesse Winchester. She remains among the finest interpreters one will ever hear. Some of my disappointment in her subsequent work is a consequence of her decision to become a singer-songwriter, which in my hearing hasn't particularly suited her. Not that she can't write an exceptional song, but back then she practiced quality, not quantity.

So the issuance of Ramble in Music City will thrill all those who loved Harris in her prime. It's a 1989 live recording, forgotten till recently by all concerned (which seems, frankly, incredible) and performed at Nashville's Ryman Auditorium. She and a crackerjack acoustic band, including such towering figures as Sam Bush, John Starling and Roy Huskey Jr., revisit songs Harris was singing in the first decade of her career. One, "If I Could Only Win Your Love," is from its very beginning.

She and the boys do an outstanding job, to put it as un-hyperbolically as one can. Clearly they are having a very good time, and undoubtedly so will you.

Harris's return to her roots followed advice from her friend the late John Starling (long a mainstay of the Seldom Scene), who encouraged Harris, then exhausted after years on the road and uncertain of her musical direction, to return to a bluegrass-based approach. If Ramble is not exactly a bluegrass record, many of the players were genre veterans, and bluegrass touches are ubiquitous. The songs represent Harris's eclectic but almost infallible appreciation for first-rate songcraft; I say "almost" because in my judgment Van Zandt's "If I Needed You" is sappy and irritating. Yes, I don't doubt this is very much a minority opinion, but there it is.

Among my favorite Harris covers, on the other hand, is "One of These Days," surely as solid a country song as any ever conceived, far removed from the hackiness that defines much country material, even some of the classic stuff. None of us would have heard it, though, if Emmylou hadn't and then brought it into her repertoire. Harris encountered it as a George Jones B side composed by Earl Montgomery, brother to Jones's pre-Tammy duet partner Melba Montgomery.

Beyond that are the hymns ("Wayfaring Stranger," "Green Pastures") and folk songs ("Hello Stranger") with Harris's indelible interpretations; dazzling covers of hardcore country ("Blue Kentucky Girl" from Loretta Lynn,"Sweet Dreams" from Patsy Cline); memorable modern folkish anthems ("My Songbird" from the late Jesse Winchester, "The Boxer" from Paul Simon, "Boulder to Birmingham" from Harris herself). There is, moreover, a gorgeously realized pop tune, Doc Pomus's "Save the Last Dance for Me."

Ramble in Music City's presentations of previously recorded numbers rival, sometimes surpass, the studio originals. All movement ceases as their sound expands outward into the room. By the time it's over, we have been graced with an hour and 15 minutes of Emmylou Harris's excellent company. In the twilight of a remarkable career, she has gifted us with this, destined to be ranked among her essential albums.