“Reckless” is the brazen and instant theme song for Kassie Krut. “K / A / S / S / I / E / K / R / U / T / T / T / T,” Alpert sing-spells, almost tauntingly, over a chunky drum machine peppered with serrated effects. Retaining the fanged snarl of prior work, “Reckless” outlines sugary melodies with visceral electronic flourishes, satirizing the lexicon of pop egoism while acknowledging its effective power. The result resembles a frantic transmission received from a rickety spaceship.