JOEL GOING UPTOWN WITH CLASSICAL BENT.(LIFE & LEISURE)

Byline: AL BRUMLEY Dallas Morning News

``Streetlife serenader . . . needs no orchestration,'' Billy Joel once sang. ``The melody comes easy.''

Melodies are still coming easy to this prolific piano man, who has been in the music business more than 30 years and releases his third greatest-hits package this week.

Now, however, the man once described by Billboard as the ``Irving Berlin of rock 'n' roll'' says he's ready to start taking a closer look at that bit about orchestration.

Joel now is touting ``Greatest Hits, Volume III.'' He's scheduled to appear at Tanglewood's Osawa Hall on Oct. 4 at a benefit for Berkshire Theatre Festival, details of which will be announced soon, and he's touring on an upcoming series of dates with Elton John. Joel says once he's done with that, he plans to concentrate on classical music.

``Well, I've been writing …