Sleep Song

``Sing song sing song/ Listen to the sun yawn,'' begins this lyrical, sweet bedtime book. Ray's (To Cross a Line) quiet litany of rhymed couplets accompanies Mitchell's (Rain Feet; Joshua's Night Whispers) lifelike if somewhat drab portraits of a rosy-cheeked, androgynous toddler as he/she is patiently put to bed by both parents. Following a look at the clock (``Tick tock tick tock/Listen to the hall clock''), the family embarks on their evening routine: ``Bath time bath time/ Listen to the words rhyme''; and the more enigmatic ``Scrunch low scrunch low/ Listen to the search grow.'' At the end, the parents are silhouetted in the doorway as the sleeping baby cuddles a woolly lamb. Soothing. Ages 1-3. (Mar.)