First of two parts On a cool Sunday afternoon in late January, they gathered at the rooftop of the nondescript NCC Building in Mandaluyong City: keyboardists Elhmir Saison and Butch Saulog, guitarists Riki Gonzales and Rey Infante, drummer Rey Vinoya, and bassist Dave Harder. It was clear from the jazz supergroup lineup—first-call musicians all—that there’d...