Amy Macdonald's estimable charm hinges on a marriage between contrasts: her winsome, jangly melodies, and the unflinching eye and arch wit she brings to her lyrics. The singer/songwriter honed her chops in Glasgow cafes in her teens before releasing her 2007 debut, packed with incisive, hooky hits like “Mr. Rock ‘n' Roll,” a send-up of archetypes. On later albums, she showcases a throatier vocal approach and more nuanced arrangements, eschewing Celtic breeziness for edgier rock flourishes. Though her voice is lilting and sweet, the Scottish singer's songs pack a wallop.