At first it seems difficult to put your finger on saxophonist Gato Barbieri's current problems. But put on his incomplete "Communion" album, recorded with trumpeter Don Cherry in the early '60s (when Gato was still Leandro), and then compare it with his most recent "Alive in New York" album and you'll spot the difference immediately. It's all in the personnel.

Gato has matured, to borrow from some of Nat Hentoff's album lining prose, and his stuff has gotten more vibrant, if less free in form over the years. He has, however, traded in the top jazz back-up men for some players who would do better accompanying Bruce Springsteen. Now Gato's in town, but before you go down to Paul's Mall to see him, consider this: the last time he was in Boston he played nothing but jazz/rock including cuts from his "Alive" album, which he recorded one week after his appearance here.

Except for one bried foray into Last Tango in Paris the superb player never even touched upon a single request for his old music--not even Encuentros--to his audience's dismay.

Nevertheless Gato doesn't let up and gives you a full performance relatively unimpeded by the noise that surrounds him.

Gato's got a special added bonus for his two nightly shows at the Mall--Al Jareau. Shows begin at 8:30 and 11.

Don't overlook Charlie Byrd if you are in the market for some jazz guitar this weekend. He's at Sandy's Jazz Revival in Beverly through Saturday.