The indefatigable Weslia Whitfield is at it again, breaking new ground on her umpteenth album, September Songs (HighNote), by uniting with various combinations of sidemen to concurrently explore the songbooks of Alec Wilder, Kurt Weill and Harry Warren. Backed by husband Mike Greensill's elegantly subdued trio (the comfortable Whitfield setting we're most accustomed to) and the Gary Foster Horns, she opens with a "September Song" that's more bitter than sweet, then shifts gears, augmenting the trio with the lilting strings of the Kronos Quartet for a dreamy "Speak Low" and a splendidly clever medley of "I Only Have Eyes for You" and "Jeepers Creepers." Next, she swaps out Greensill's trio for Tommy Flanagan's for a lively spin through Wilder's wittily upbeat "Lovers and Losers." The Foster Horns then return to lend a touch of big band vivacity to "I Had the Craziest Dream." Finally, Whitfield downsizes to the comparative sparseness of her husband's duo (Greensill on piano and Michael Moore on bass) for one of the most lushly reflective versions of "September in the Rain" I've ever heard, a radiant "A Child Is Born" and, in the album's only real disappointment, a reading of "Lost in the Stars" that's disconcertingly robust. Typical of Whitfield outings, she also unearths an underappreciated treasure or two. This time around they're Warren's feathery "I Know Why and So Do You" and Wilder's unsettlingly inky "Moon and Sand," both welcome additions to the massive Whitfield canon.