Soothing and stimulating music and lights!Accordion-fold book includes a friendly light-up face on every page. Faces light up one after the other from left to right in time with the music, encouraging baby to follow along. Double sided book features simple patterns and images on one side and more advanced graphics on the other for two stages of development. Plays two different melodies, one soothing and the other stimulating, for 10 minutes before switching itself off. For use in a crib, stroller or on its own. On a mat encourages baby to lift her head and shoulders -- great for tummy time!