POP MUSIC REVIEW : Winter, McLagan Tug at Their Rock Roots : The Texan guitarist shows he can still speed-play, though he’s best when he downshifts. And the ex-Small Faces keyboardist revives that band’s party mood.

Texas guitar tornado Johnny Winter and British keyboardist Ian McLagan both play something that might be considered roots music, although those roots didn’t run any too deep when they played Thursday at the Coach House. That’s not a condemnation by any means: America’s native music is as effective a launching pad as it is a foundation. And to limited degrees, each performer has taken off on his own path.

Winter, the headliner, first attracted notice in the late ‘60s as a unique twist on the “Can a white man sing the blues?” question. While that topic raged in editorials and on the letters pages of music mags, along came Winter--an albino--who had been subjected to a more singular version of color discrimination.

At a time when the rock audience was getting most of its blues licks by way of Britain, Winter dished it up with a Texas fury, playing wild flurries of notes and roaring like a cartoon lion. It wasn’t particularly faithful to the blues it emulated; without either the raw feeling or the finesse of the real thang , his full-tilt attack typically wore pretty thin after the first few songs.

In the late ‘70s, however, Winter began working with Muddy Waters, one of his early idols, and he showed a surprising restraint and respect for form in both his playing and production on Waters’ records.

In recent years, and at the Coach House on Thursday, Winter has largely gone back to his old over-the-top approach. But, while he may be as speed-happy as ever, there is a positive change in his playing: His torrents of notes now often seem truly fluid, linked to each other in singing, expressive phrases.

His 11-number set consisted chiefly of extended jams on blues standards, some from his current “Let Me In” album. As on the album, he was accompanied by drummer Tom Compton and bassist Jeff Ganz. Both provided a steady support for Winter’s flights. Ganz’s technique-spouting bass solos didn’t add much to world culture, despite the way he prefaced each one by announcing, “Check this out!”

Winter sported a black cowboy hat atop his torso-length corn-silk hair, and a sleeveless, tie-dyed T-shirt showed off his thin, heavily tattooed arms. He kicked off the set with two long instrumentals, including a far-ranging exploration of Freddie King’s “Hideaway.”

His up-tempo version of Marty Robbins’ “Sugaree” had a loopy, celebratory mood that carried into his slash and burn guitar solo. His take on “You’re Humbuggin’ Me,” though, seemed hopelessly antic contrasted with the Fabulous Thunderbird’s steady-groove version. He strapped on one of his vintage Gibson Firebirds for an uproarious slide-guitar workout on “Mojo Boogie.”

Despite the obvious crowd-pleasing effect of his fast-flying numbers, Winter’s finest playing came when he slowed down a bit, as he did on the sultry “Blue Mood.” His solos there were oddly lyrical, with angry, stumbling lines sliding into long, sad bent notes.

One consistent debit to Winter’s performance was the sound he was getting out of his gear. Except for his bottleneck tunes, he now uses one of those high-tech headless guitars, which sound about as warm and human as a paging beeper. Then, everything he played was filtered through his amps’ swirling vibrato effect, which is ultimately about as musical as a violinist adding a heavy vibrato to each note of a concerto.

McLagan’s dyed roots come by way of American R&B; and boogie-woogie music, done up in a British pub-rock spirit. Backed by a capable trio dubbed the Bump Band, the ex-Small Faces member conveyed that band’s party mood through his pumping keyboard work and ragged, better-than-Ron-Wood-at-least vocals. Thankfully, he also projected more of an intimate beer-joint mood than the Faces’ old arena sprawl.

In his post-Faces career,McLagan has provided keys for the Rolling Stones and others, including some of Bruce Springsteen’s recent recording sessions. He barrelhoused some fine fills into a Booker T. instrumental, some originals and some classic Faces material, including the Rod Stewart-era “You’re My Girl” and the ‘60s Small Faces classic “All or Nothing.”

It’s too bad McLagan didn’t have a tune called “Johnny Winter,” because he was certainly getting several requests for it. Unfortunately, due to a snafu, there was one more opening band on the bill than anyone expected--a group called John Wayne, which played a set of island-inflected rock that was well-performed but about as necessary as Men at Work--and the night was wearing heavy on Winter fans by the time McLagan came on.