We have an enigma in Franck Amsallem. Born in Algeria, he has lived most of his life in the United States. Usually his albums are devoted to his excellent originals, but for Summer Times (Sunnyside) his sources for most of the tunes are as American as they come: “Jazz via Tin Pan Alley.” That’s a quote from his notes, which sound remarkably like his keyboard style: laid-back, yet brash; simple, yet complex; unassuming, yet confident; and above all, original. With sympathetic backing by bassist Johannes Weidenmüller and drummer Joe Chambers, Amsallem visits Gershwin three times: he turns the first four notes of “I Got Rhythm” into an ostinato launching pad for a way-up romp, repeating the motif in various forms; “Summertime” receives a refreshing 5/4 treatment; “The Man I Love” is given a Calypso makeover. Amsallem is always thinking, but the emotional highlight comes on the introspective “Young and Foolish.” A ballad always separates the man from the boy, and the multilayered Summer Times is all human.