'Tuck Everlasting,' the new musical that deals with eternal life, has wisely been put in the hands of someone whose work on Broadway never seems to die -- director Casey Nicholaw...The show that opened Tuesday at the Broadhurst Theatre is wonderfully crafted, a Nicholaw hallmark. Poignancy mixes well with humor, the songs are fresh and sweet, the set is blissful and the performances honest. It has a polished feel. All of the parts work smartly...The music by Chris Miller is magical, grounded in folk, foot-pounding earthy beats and soaring melodies...Nathan Tysen's lyrics are even better -- delving into complex themes with elegance.