Why?, They Might Be Giants' first children's album in six years, was also their second full-length of 2015, arriving shortly after the wonderfully dark and weird Glean. Like that album, Why? doesn't shy away from danger and disaster (two of the possible consequences of discovering the answer to the title's question). On "Oh You Did," Robin Goldwasser sings a growing list of too-late warnings ("Don't drop eggs from the 14th story window -- oh, you did") with the weary patience only a mother could muster, while "I Made a Mess" embodies the heart-stopping panic of trying to fix the unfixable in its staccato verses. Elsewhere, precious collectibles get knocked to the ground ("Long White Beard") and a farmer suffers the consequences of building a farm in the middle of an elephant migration path ("Elephants," which is sung by bassist Danny Weinkauf). Given that this is a kids' album, Why?'s mood is notably lighter than Glean, and songs like "Omnicorn" are full of the sunny, jangly pop that defines TMBG's music for their smaller fans. At times, it feels like the band is trying too hard to be lighthearted: "I Just Want to Dance" and "Moles, Hounds, Bears, Bees and Hares" are cute, but not as distinctive as their best children's songs. Fortunately, Why? includes a couple of higher-concept songs that are unmistakably They Might Be Giants: "I Haven't Seen You in Forever" is a round that puts the truisms "absence makes the heart grow fonder" and "familiarity breeds contempt" into action with simple and complex results; "Thinking Machine" is weird and whispery, full of absurdism and tautologies that make it an enticing gateway to surrealist pop. Why? may be the band's first album for kids without an overtly educational theme since the instant classic No!, but its glimpses of familyhood are perhaps even more important in their own way. Some songs get into a kid's headspace perfectly: "Definition of Good" imagines ping-pong balls as eyes; "I Am Invisible" will remind listeners of all ages of trying to disappear from sight by walking on tiptoe and holding one's breath; and "So Crazy for Books" captures the euphoria of falling in love with reading. Other songs take a broader perspective: "And Mom and Kid" is a bear hug of a song that holds all the different combinations of kids, parents, and grandparents that make up a 21st century family in its embrace, while "Then the Kids Took Over" ends the album on a hopeful, eco-friendly note, with "that's when the future began" as its rallying cry. Why? isn't quite as brilliant as No!, but there's no question that it's another rewarding addition to their collection of children's music.