Famed songwriter Irving Berlin, who observes his 100th birthday anniversary this week, has become a legend in America and many other countries. And deservedly so.

Berlin, the Russian-born composer whose name has become synonymous with Tin Pan Alley for his classic songwriting on tunes such as "White Christmas," "Easter Parade," "There's No Business Like Show Business," and "God Bless America," has been seen less and less in public through the years.Although he was born in Russia, he came to Amerca with his parents at age 2 and was passionately patriotic about his adopted country - a feeling that often found voice in his music.

On his 74th birthday the composer, who wrote more than 1,500 songs and who managed to match the changing moods of a nation for more than half a century, said he shuddered to think of the thoughts of retirement. "You can't retire when you are still able to work," he said emphatically.

His song total is unmatched by any other composer. As impressive as the sheer quantity is the quality as well.

Many aspiring composers and other writers would do well to follow Berlin's recipe for success, described by Morton Gould, president of the American Society of Composers, Authors and Publishers:

"His songs have the sophistication of simplicity. You know precisely what he's saying and singing. He's been able to distill everything down to its essence . . . He expresses emotions that human beings would like to experience . . . ."

Those old enough to remember the popular hits of Irving Berlin wish he were still turning out music as he was years ago. But they recognize that long after he is gone that his music will live on in the minds and hearts of people for generations to come.

We wish him a happy 100th birthday. Few people live that long; but very few at any age manage to produce such a wonderful legacy.