TEMPERATURES soared outside the Division Street Grill in Peekskill on a recent Saturday night. But inside, the unflappable guitarist Bucky Pizzarelli and his longtime bassist, Jerry Bruno, were playing it cool with well-worn standards like “Satin Doll” and “Tangerine.” And their subtle, sly treatment struck a chord with the 40 or so diners, who applauded faithfully between bites of pan-seared tuna and penne Bolognese.