Even by the fluid-personnel standards of jam-band culture, the pianist-organist Marco Benevento gets around a lot: with the Benevento/Russo Duo, his longtime improvising project with drummer Joe Russo, and in a whirl of collaborations, on stage and record, with like-minded souls such as Phish bassist Mike Gordon, Galactic drummr Stanton Moore and jazz trumpeter Steven Bernstein. One very late night in April, at the French Quarter branch of Tipitina's in New Orleans, I caught Benevento in a funky-space quartet, featuring trombonist Mark Mullins of Bonerama, swinging non-stop through tunes by the blues-piano genius James Booker, second-line struts and the leader's abstract treated-keyboard reveries. But on his studio records with his regular trio, bassist Reed Mathis and drummer Andrew Barr, Benevento jams with a concentration on the textures and colors available in his keyboards and arsenal of manipulated pedals and effects. Between the Needles and Nightfall (Royal Potato Family), his latest release, is deceptively rich — catchy melodies and straight-ahead grooves ("Greenpoint," "RISD") that expand with subtle mounting gestures: lapping-water echo, curdled mellotron, the falling-star electronics at the end of the waltz "Music Is Still Secret." There is, I should note, nothing shy about the piano-trio fury of "Wolf Trap," which is what Emerson Lake and Palmer might sound like if they'd made their bones at Bonnaroo.