Natalie Merchant’s first studio album in seven years is a collection of children’s poems set to music, but Leave Your Sleep is a far more substantial and resonant creation than that description might imply. These 26 tracks marry texts by writers both famous (Robert Lewis Stevenson, e.e. cummings, Odgen Nash) and obscure to musical styles ranging from Cajun to Celtic to classical. Merchant brings out the dark shadows and sweet absurdities in these verses, veering from the silly (Calico Pie”) to the ominous (“The Sleeping Giant”) and tragic (“Spring and Fall”). “Autumn Lullaby” and “Maggie and Milly and Molly and May” are especially haunting and otherworldly. When Natalie cuts loose, she fills tracks like “Adventures of Isabel” and “The Peppery Man” with great zest and jauntiness. Wynton Marsalis, Medeski, Martin & Wood, the Klezmatics and the Fairfield Four are among the diverse cast of guest musicians here. By turns whimsical, eerie and poignant, Leave Your Sleep is a work of great ambition, filled with youthful imagination and adult wisdom.