Japanese pianist and composer Hiromi is one of the more unpredictable, captivating talents in modern jazz. Her Trio Project with drummer Simon Phillips and contrabass guitarist Anthony Jackson, now into its sixth year, has matured into one of the most fluidly inventive on the scene. Spark, recorded over four days in October of 2015, is the group's fourth offering. Like its predecessors, it has a loosely connected thematic scheme. In this case, it's the spark of inspiration that leads to creation, risk-taking, spiritual connection, and development via an album-length dream sequence. The established hallmarks of the trio are abundant -- tight, twisting, turning, sometimes incendiary dialogue in constantly evolving themes and motifs that embrace everything from post-bop to proggy rockisms to funky soul-jazz. The title track is introduced by an inquisitive, nocturnal piano figure before a wash of electric keyboards enters underneath, and the band is off, playing one theme after another in widening circles. Hiromi's invention in the lower and middle registers resonates with Jackson's roiling bass patterns, Phillips' syncopated breaks, and insistent fills that never lose the pocket. "Take Me Away" has a trance-like repetition in its intro. It expands its textural foundation with Jackson playing guitar-esque fills and Phillips riding the snare and cymbal as agents of hypnosis. A sweeping refrain, followed by a knotty bridge that leads to a crescendo, introduces a souled-out groove that recalls Ahmad Jamal. The trio swings on a vamp played by Jackson. The percussive pulse of "Wonderland" gives way to something approaching a classical fugue before opening wide into expansive post-bop then folds back again before Hiromi takes her solo. It's rife with emotive arpeggios and fluid harmonic investigation. The rhythm section swings hard, adding dimension via extension and extrapolation. Phillips uses octobans -- high-tuned tom-toms -- to create a near theatrical fantasia that the pianist answers with high-wire lyricism and choppy chords. Drama and dynamic are in constant conversation on "Dilemma." Pulse, speed, and force are balanced by moments of near sublime inquiry as the lines between jazz, prog, and classical crossover vanish. The uptown electric jazz funk of "What Will Be, Will Be" feels light in contrast. A careful listen reveals the influences of Stevie Wonder and Herbie Hancock in its finger-popping groove consciousness. Closer "All's Well" is based on a swinging midtempo blues. It pushes boundaries on all sides yet never sacrifices feel. Spark integrates each element in this band's arsenal to create a whole that is provocative and seamless. Hiromi's band challenges modern music norms with authority. Their spirit of restless creativity is expressed with as much warmth and humor as technical acumen. The tunes here, though rigorous musical workouts, all reach the level of song -- not an accomplishment most piano trios can claim.