Jazz is not always a pleasant experience -- it wasn't, even before the sometimes-queasy experience we call "fusion." There are times (and perhaps they are its best times) when America's unique contribution to the international resources of serious music reaches deep into your soul with a raw cry of rage, with an anguish beyond words.

But jazz is many kinds of music, and through tomorrow night, with pianist George Shearing in residence, the jazz at Blues Alley is, above all, enjoyable. I say this not in dispargement; at a time when pleasant music is a commodity in very short supply, that is no small claim.

Strictly speaking, Shearing is probably an entertainer whose basic medium happens to be jazz, but he is technically expert and gifted with a bright but carefully disciplined imagination that masks his art's affinities to the standard cocktail-louinge piano. What he does is well done, and who is qualified to tell him he should attempt to do more?

Besides playing the piano (with thoughtful accompaniment and occasional fine solo excursions by bassist Brian Torff), he did a passable vocal a la Bobby Short on "Let's Do It" with updated lyrics ("teen-agers squeezed into jeans do it: Probably we'll live to see machines do it").

One of the keyboard highlights was a performance of "Happy Days Are Here Again," done very slowly as Streisand recorded it, but finding in the melody a few nuances that she missed in her leisurely exploration.