In his deepest private moments, Mick Jagger will confess to how hard it is to keep a band�s legacy alive as he pauses to endorse another check. Such long-running ventures � ghost bands excepted � are much more rare in improvised music. Players drawn to this kind of music tend to have an omnivorous curiosity that resists musical inertia. And the shortage of playing opportunities virtually guarantees that the financial resources to go on and on and on won�t be there. This is probably a good thing; it saves the music from the sad spectacle of ... well, the Stones, for instance. But a band concept is a seductive thing, especially when that concept was as novel and powerful as George Cartwright�s Curlew. Formed a quarter-century ago in the hothouse of New York�s downtown scene, Curlew might once have been defined by what it was not � namely, a jazz band (too defiantly unidiomatic), a rock band (no vocals and a saxophone-cello front line) or a chamber ensemble (too loud). Curlew was the very embodiment of No Wave. So how do you keep all this negation alive after 25 years, numerous personnel changes and a move to Minneapolis (by way of Memphis) That�s the puzzle of Mercury. It helps that original member George Cartwright�s tenor saxophone still has the incendiary moonshine tone of the old days. And Memphis' Chris Parker recalls the dada of guitarist Davey Williams, especially when he dials-up the arena rock voice on his synth to play a screaming, irrational solo. But irrationality is what is missing on Mercury. The rhythm section of bassist Fred Chalenor and Cartwright�s old Mississippi pal, drummer Bruce Golden, is fine, but they are almost too well organized. You don�t get the sense that the manic episodes could erupt at any minute, despite the fact that all the outward elements of the Curlew style are here. There�s enough similarity to the old Curlew to highlight what�s not there. And what�s not there, unfortunately, is the late cellist Tom Cora, who with the perspective of time, increasingly seems like the heart of the old band. George is still George, but he can�t carry the load all by himself.