The sassy, catchy “Mercy” and the aching “Syrup & Honey” show traces of Marvin Gaye and Aretha Franklin, but Duffy sounds most like herself on “Delayed Devotion,” a song that forgoes nostalgia and delivers instead a very sharp and well-written contemporary pop song. Elsewhere, spacious, string-laden songs like “Distant Dreamer” and “Rockferry” owe much to producer Bernard Butler’s former band Suede.