Summer Night (Naxos Jazz 86071-2; 50:38) finds Sarah Jane Cion in very good company, with bassist Phil Palombi and this column’s recurring drummer, Billy Hart. There is a formal elegance to Cion’s playing that gives these performances an engaging smoothness. Not that this is smooth jazz: pieces like “Stage One,” with its aggressive ensemble theme, have far more energy and authenticity than that category can handle. Smooth here means no loose ends, no unresolved questions. There are plenty of variations on Summer Night, plenty of inflection, but the essential nature of the recording is placid, even with the musings of Michael Brecker’s tenor on a “Summer Night” full of anticipation, and the almost elegiac “Prisoner of War.” Cion’s writing is in many respects the better part of her program: though her technique apparently gives her ideas full access to the keyboard, greater dynamic range and more risk-taking may figure in as her style matures further.