Nancy Sinatra's pop career began with spun-sugar singles like the string-laden ballad “Like I Do” and the longing “Think of Me.” But her true breakthrough came in 1966 when she released the slow-building kiss-off “These Boots Are Made for Walkin',” a hip-swiveling slice of jazz-pop penned by Lee Hazlewood. The producer/composer was at the helm of Sinatra's shimmering cover of “Bang Bang (My Baby Shot Me Down)” and the dreamy “Sugar Town,” while the pair's hazy duet “Some Velvet Morning” gives country-pop a psychedelic tinge. Her duets with her father, Rat Pack heartthrob Frank, show off her sweet side.