Marcel X. "Jack" Rocca, 75, a well-educated entrepreneur who owned and ran a Washington language school and translation service, among other ventures, died of non-Hodgkin's lymphoma Oct. 28 at his home in Bethesda.

Mr. Rocca's idea for a commercial language school came to him while he was tutoring foreign students in English as a graduate student at Georgetown University in the mid-1950s. He started the Institute of Modern Languages of Washington in 1960.

The commercial language school, among the first of its kind in Washington, opened a branch in Mexico City and expanded its services to include language translation for government agencies and private companies.

Its students included government officials and foreign diplomats, including the current president of Colombia, Alvaro Uribe Velez.

In 1969, American Express Corp. bought the institute from Mr. Rocca, who continued to head the school before leaving to start his second company, Transemantics Inc., which he sold in 2003.

While the new business was much like the old one, he also began to produce multilingual recorded audio tours of Washington, and he opened a private high school called the Washington Academy.

He also started an advocacy group called the Organization for the Advancement of Small Independent Schools.

Mr. Rocca was a trustee of Davis & Elkins College in Elkins, W.Va., and was a Cub Scout and Boy Scout master.

In the 1980s, he dusted off his trumpet-playing skills and formed the Metrotones, a Dixieland jazz band, which performed at Washington area restaurants and retirement homes through the 1990s.

Born in Belleville, N.J., and raised in Leominster, Mass., Mr. Rocca was educated in public schools but also earned academic scholarships to attend summer sessions at Phillips Exeter Academy in Exeter, N.H., and Phillips Academy in Andover, Mass.

He went on to Harvard University, where he counted Henry Kissinger and James Schlesinger among his classmates. Mr. Rocca graduated from Harvard with a degree in English and American literature, then attended Harvard Law School for a year before entering the Army at the time of the Korean War. He served in Japan on grave registration duty.

After fulfilling his military duty, Mr. Rocca spent a year working in Taiwan as an information officer for the U.S. Information Agency.

He received a master's degree in Japanese studies from Georgetown University in 1956. He received a law degree from Catholic University in 1967.

Survivors include his wife, Maria-Luisa Villar Borda of Bethesda; three sons, Francis Xavier Rocca of Rome and Lawrence Edward Rocca and Maurice Alberto Rocca, both of New York; two sisters; a brother; and a grandson.