BY STEVE MORSE
Boston Globe

MOST SUPERGROUPS tour and then take some serious time off. Ask the Rolling Stones and U2 about that. But not all supergroup members go quietly into prolonged vacations and private mansions. Stevie Nicks finished Fleetwood Mac's tour last winter but is now touring again, propelled by her three-CD box set ``Enchanted,'' which came out in April.

``It's easier for me to just keep going than for me to stop and do nothing for a couple of months. You know what I mean?'' says Nicks, who plays Mountain View on Saturday and Concord on Sunday. ``It's better for me to just keep working.''

Nicks' workaholic ways could be surmised from the song ``Sweet Girl,'' which she wrote for Fleetwood Mac last year. It contains a verse that defines her life: ``I chose to dance across the stages of the world/ Sometimes I think I was always on call.''

The call this time came from Atlantic Records, which has issued Nicks' six solo albums and wanted a finale before Nicks bolted to her new label, Warner/Reprise. The idea of a boxed set was raised. Nicks at first wanted to do a five-CD box but settled for three -- and a handsome three, at that, since they include eight previously unreleased tracks and 20 songs, overall, that have never appeared on a Nicks album, ranging from B-sides to live and soundtrack cuts. These are joined by her 12 Top-40 hits, such as ``Stop Draggin' My Heart Around'' (a duet with Tom Petty) and ``Edge of Seventeen (Just Like the White Winged Dove).''

``Atlantic wanted to put it out now,'' Nicks says by phone from Los Angeles. ``So I thought I'd do it as quickly as possible and still try to do it beautifully. Then go out and do a three-month tour, then come back and start on my next record.''

Chronicle of drama

The songs span passionate times, jilted times, druggy times -- and all the rest of the highs and lows that have characterized this Phoenix native's rags-to-riches, rock 'n' roll life.

``All these songs are about some heavy stuff,'' says Nicks. ``There isn't a song in here that isn't about something intense. To hear all the songs in a group, I didn't even realize that my life was that intense. When I proofread all the words for the songs, I went, `Wow, even I'm amazed that you're still alive.' ''

And, yet, Nicks isn't complaining. Which is why she titled the box ``Enchanted'' (also the title of one of her songs, though the title for the box was suggested by her brother, Chris). Says Nicks: ``I have always considered my work and my life somewhat enchanted.''

The box is not chronologically arranged but does include the song ``Rose Garden,'' which Nicks wrote when she was 17. It was the second song she ever wrote.

Life story a surprise

``I had no idea about fame or fortune or anything else back then. All I had was my own life,'' says Nicks, who turned 50 on May 26. ``I had no idea I would become famous and own big houses and acres of land and have men and money, though what I wouldn't have would be that great love of my life, because that great love of my life wouldn't be able to hang out with my lifestyle.''

Speaking of lifestyle, Nicks has had several rock-star lovers through the years -- Lindsey Buckingham, Mick Fleetwood and Don Henley -- but there's a B-side on the boxed set, ``One More Big Time Rock Star,'' that cynically says, ``just what I need.'' The song is about a rock star who sends flowers instead of showing up himself. Nicks won't name names in this case.

``It's such a rock-star thing to send flowers. It's sick to send a $150 arrangement of flowers and think that that's going to make it OK,'' says Nicks. Of such an individual she adds: ``Nobody needs one of those. They are a pain.''

The box set comes with the obligatory booklet, but it's not crammed with the kind of gossipy insights that other booklets have. ``I'm not a big confession person. I don't feel I have to confess all my sins to the world,'' says Nicks. ``I've never been that way. I'm different from Lindsey (Buckingham) in that way. I mean, he likes to confess everything. We just feel differently about it.''

The box is highlighted by several previously unreleased demos. One is ``Twisted'' (featuring Jesse Valenzuela of the Gin Blossoms on guitar), about someone ``chasing down the demons, crying out for love.'' Another is a terrific rockabilly cover of Dorsey Burnette's 1959 tune ``It's Late,'' where Nicks shows the vocal power for which she's famous.

The new single from the box, ``Reconsider Me,'' is a Warren Zevon love song recorded in 1987 with a backup vocal from Henley, but it's never been released before. It was a source of conflict at the time with Nicks' longtime producer, Jimmy Iovine.

``When Jimmy brought me the song, he thought it was going to be a key song in my career, like a second `Stop Draggin' My Heart Around.' But we got in a big fight because I really don't like to do other people's songs that often. That's why I write my own songs. I was pretty crazy at that point in my life, and you couldn't tell me anything. And I said to him, `I would never say the words ``reconsider me'' to somebody. I would never ask somebody to reconsider loving me.' Well, he thought that was the biggest bunch of crap he'd ever heard; so we had a big fight about it, and that's just about the last time Jimmy and I ever worked together.

Mellowed with age

``But all these years later, I'm not uptight about it anymore,'' Nicks adds. ``And Zevon was a very good friend. . . . I'm delighted to be doing Warren's song now.''

Nicks clearly has matured through the years. That was evident on the last Fleetwood Mac tour, where she starred on many nights. She hopes the Mac will tour again one day, even though she admits that band-mate Christine McVie is reluctant to do so. ``And I would never go out without Christine. She is just too much a part of it,'' says Nicks. ``But in my heart of hearts, I don't feel this is the end. I just feel that everybody is resting right now.''

Stevie Nicks With Michael McDonald