By BEN SISARIO

A few years ago Hicham Chami, a young musician in Chicago who was researching early-20th-century Arab music, found some melodies he recognized from his school days in Morocco. The words were slightly different, but the music was unmistakable. And most important, it had a composer.

"I always thought this music belonged to the traditional repertoire," Mr. Chami said. "There was no credit given to any composer; it was just a melody out there. But I was surprised to realize that all these melodies have a composer, and it happened to be Sayyed Darweesh."

Darweesh, a furiously prolific Egyptian composer who died at 31 in 1923, is one of the most influential figures in modern Arab music. He earned a wide reputation as much for his short but eventful life as for his cosmopolitan, Western-influenced music. An advocate of the working class when Egypt was occupied by Britain, Darweesh — whose surname is sometimes rendered as Darwish, and his given name as Sayid or Sayed — wrote about women's suffrage and class disparities, and composed the theme that would become the Egyptian national anthem. He was also a cocaine addict who died before achieving his goal of traveling to Italy to study opera.

Mr. Chami and his group, the Chicago Classical Oriental Ensemble, have recorded "The Songs of Sayyed Darweesh: Soul of a People" (Xauen) and begin a national tour tomorrow at Symphony Space.

"He is famous for the kind of life he had," Mr. Chami said. "He was famous for the kind of death he had. He was famous for the kind of lyrics he was writing. But he was not famous for what I think should be the essence of his fame, which is having composed these songs and these melodies that are being sung from North Africa to the Arabic peninsula — in different languages, and with each nation adding its particular flavor."

Writing classical pieces for small ensembles as well as operettas for the theater troupes of Cairo, which in the early 20th century entertained a varied international audience, Darweesh developed a modern, polyglot style. He called himself Egypt's Verdi, and in his lyrics he tinkered with language, mixing in regional colloquialisms as well as bits of Greek and English.

As played by the Chicago Classical Oriental Ensemble — an eight-piece group that includes the zitherlike qanun (played by Mr. Chami), oud, tambourine and nay (flute), as well as cello and male and female vocals — the music is delicate and sometimes dour, with arialike melodies blended in.

"He changed the course of the standard composers before him," said George Dimitri Sawa, an ethnomusicologist in Toronto who studies Middle Eastern music. "What he did is not only standard classical songs, but he decided to sing for the people. First the French came to Egypt, then the British. He composed songs about poor Egyptians who could not find work."

Among his friend-of-the-working-man songs are a cycle devoted to modern jobs. One, "Il-Shayyaleen," recorded by Mr. Chami and his group, describes the frenzied workday of a porter who has to hustle for clients but must also cooperate with his comrades, or else everyone will lose out.

"He was saying this so long before unions came in," Mr. Chami said. "This was singing about how when you are among a group of people, you have to start thinking as a group."

Born in Morocco, Mr. Chami moved to Chicago at 22 to study for an M.B.A. at DePaul University. He continued his musical studies on the side, until he decided four years ago to jettison his day job creating marketing campaigns for shampoos and detergents, and to pursue Arab music full time.

Mr. Chami, now 28, and the members of his group, who come from various parts of the Middle East, say they took on the project partly to keep a fading tradition alive, and partly to promote the idea of a pan-Arab influence that connects the nations of North Africa and the Middle East through an adventurous, multicultural music.

Kareem Roustom, 34, who plays oud in the group and is its musical director, also noted that the music can promote American understanding of the 20th-century Arab world, which struggled with independence, adapting to the industrial age and absorbing diverse cultural influences.

"Darweesh would be a good conduit for cross-understanding," Mr. Roustom said. "It helps to understand a people through somebody they hold dear."