Composer John Adams, at 56, “is now old enough that the major works of his youth and early maturity are coming into focus as bright, certain lights from a confused and confusing time.” Lincoln Center is showcasing Adams with a festival – its first devoted to a living composer. “There will be concerts, films and ballets in four auditoriums as well as the first New York performances of Mr. Adams’s most recent dramatic score, the ebullient Christmas opera-oratorio ‘El Niño,’ at the Brooklyn Academy of Music. Forget about Mostly Mozart: this is Absolutely and Adamantly Adams. The festival should help listeners recognize what makes Mr. Adams’s music so special — and what made it so special right from the first.”