NEW YORK — When Billy Joel songs provide the entertainment for the evening, he's usually the one onstage. Earlier this month, however, he was in the audience listening to a Broadway musical-in-progress that will feature between 15 and 20 of his songs choreographed by Twyla Tharp.

After this private night at the theater, Joel green-lighted the show, tentatively titled "The Thoel Project." The musical (see [article id="1444382"]"Musical To Incorporate Billy Joel's Pop Hits"[/article]) is being produced by the Nederlander Organization theater empire and will likely be previewed early next year in another city for four to six weeks before beginning its Broadway run, a production spokesperson said.

"Twyla put it all together from the material I wrote and recorded over my whole career," Joel said backstage during Saturday's Concert for New York. "I thought it was pretty good, but how objective could I be?"

Tharp and Nederlander discussed the idea of a musical centered around Joel's songs for two years before the Piano Man was contacted. While Joel's involvement will be minimal, his approval was necessary.

With minimal dialogue, the show uses Joel's music to tell the story of three friends growing up during the '60s who get shipped off to Vietnam, the spokesperson said. When one is killed, the two survivors are torn apart. After becoming ensnared in the '70s drug scene, they straighten out in time to greet the next decade.

Well-known Joel songs in the production include "An Innocent Man," "Big Shot," "The River of Dreams" and "Movin' Out (Anthony's Song)." The musical features a live band fronted by Las Vegas vocalist Michael Cavanaugh, who is said to sound eerily similar to Joel.

Dance styles for the project range from ballet to modern dance to disco.

The double-album set The Essential Billy Joel, which contains some of the songs that will be used in the musical, is #38 this week on the Billboard 200 albums chart.

Joel also has the #1 record on Billboard's Top Classical Albums chart. Opus 1-10 Fantasies & Delusions (Music for Solo Piano) consists of Joel compositions performed by pianist Richard Joo (see [article id="1448500"]"Billy Joel Speechless On New LP"[/article]).

"It feels great [to have a #1 album] because I started out playing classical piano," Joel said. "So for all my teachers that told me I'd never amount to anything — ha!"