An occasional update of theater openings
* AN EVENING WITH RAY DAVIES: 20TH CENTURY MAN - (At the Westbeth Theater Center in New York through March 3): Pop-music fans get a rare treat in this intimate evening with one of the greatest songwriters in rock history, Ray Davies of the Kinks. As part of a national tour, Davies is performing his (almost) one-person show, ''20th Century Man,'' at a small Off Broadway theater. Based on his recent autobiography, ''X-Ray,'' the show is a blend of readings from the book, chatty anecdotes about the early history of the Kinks, and renditions of such classics as ''You Really Got Me'' and ''Lola,'' as well as new material. (He is accompanied by guitarist Pete Mathison.)
It's amazing to see a pop-music figure of this magnitude in such relaxed circumstances; it's like sitting in Davies's living room as he tells you the story of his life. The theater is decorated in English music hall style, and the evening reminds one of how much Davies was influenced by that style. His amusing accounts of the band's early days, his frequently rancorous relationship with his brother Dave, and his experiences during the band's first American tour prove him to be a engaging storyteller as well.
* BIG - (At the Fisher Theatre in Detroit through March 10): This is a new musical adaptation of the 1988 film, which starred Tom Hanks as a kid who gets his wish to be ''big'' and suddenly finds himself in an adult body. The highly anticipated show is receiving a lengthy tryout in Detroit before it moves to New York, where it opens officially on April 25. The $10-million show features a stellar production team: music by David Shire (''Baby''), lyrics by Richard Maltby Jr. (''Miss Saigon''), book by John Weidman (''Pacific Overtures''), choreography by Susan Stroman (''Crazy For You''), and direction by Mick Ockrent (''Me and My Girl''). Although the music could be stronger, and the show needs some fine-tuning and pruning, the delightful story works beautifully as a musical. Daniel Jenkins gives a charming performance in the lead role. ''Big'' already looks like a hit.