“Sneha,” a haunting ballad first recorded in Thailand in the mid-1960s, has become an iconic standard in that country and beyond. It occupies a pivotal spot right in the middle of Kengchakaj Kengkarnkja’s Lak Lan. Sung without artifice by Sirintip Phasuk, the Thai lyrics convey the hesitation of one who recalls a heartbreak but dares...