Pianist and jazz restructuralist Misha Mengelberg has received much acclaim for everything from his solo performances to his leadership of the Dutch ICP Orchestra, but the small-ensemble recordings he began making in the U.S. during the '90s are perhaps the best places to begin investigating his wonderfully offbeat charms. Four in One, recorded in September 2000 and subsequently released in "Super Audio CD" format by the Songlines label, is an album with particularly wide-ranging appeal, satisfying for listeners with tastes ranging from the avant-garde to more traditional post-bop, and certainly anyone interested in the commonality between Mengelberg and one of his primary influences, Thelonious Monk. The half-American, half-Dutch quartet (shades of Gerry Hemingway), featuring Mengelberg's longtime co-conspirator Han Bennink on drums and New Yorkers Dave Douglas on trumpet and Brad Jones on bass, is a perfectly compatible foursome. A few scattered free rhythmic episodes aside, Bennink is in nearly straight-ahead mode throughout the disc, curbing the subversions and hijinks he often throws into the ICP mix in favor of a consistent, highly charged swing. Jones' walking basslines push the ensemble through the chord changes at a sprightly pace, providing a foundation that effectively balances the freewheeling solo flights from Mengelberg and Douglas. And those solos are freewheeling indeed. Mengelberg's idiosyncratic sense of timing, phrasing, and melody are on full display begin