Violinist Willi Boskovsky, a master of waltz music and a longtime conductor of the Vienna Philharmonic's popular New Year's concerts, has died at 81. Friends said he died after suffering a third stroke last Sunday in a Swiss hospital.

Born in imperial Vienna in 1909, Boskovsky joined the Philharmonic in 1933. Three years later, he was named concertmaster. In 1954 he succeeded Clemens Krauss as conductor of the New Year's concerts, a tradition that he continued until his retirement in 1979.Also lost to the arts:

- Ruth Page, 92, Chicago choreographer and ballerina. She danced widely in the '20s and '30s, choreographed for international companies, and founded the Chicago Opera Ballet in 1956, which continued as Ruth Page's International Ballet until 1970. Her "Nutcracker" remains an annual Chicago event, and her Ruth Page Foundation School of Dance will continue.

- Nick Vanoff, dancer and producer of award-winning Broadway theater and TV variety shows, in Los Angeles, of heart failure, at 61.

- Alfredo Campoli, violinist, at 84 in London. A child prodigy, he performed until he was 75.

- W. Lamar Alford, actor/tenor who made his Broadway debut in "Godspell" and also sang with the New York City Opera. He died in Atlanta, Ga., at the age of 46. Cause of death was not disclosed.

- OPERA BOOMED IN THE '80s, according to a recent profile of 95 professional member companies of Opera America. Attendance grew, a trend arts leaders expect will continue if companies maintain and improve their commitment to artistry and fund-raising skills.

Moreover, opera appears to be the fastest-growing classical art form in the country, with enormous interest. Total attendance for main season and festival performances of opera increased 60 percent between 1983 and 1988 (from 2.4 million to almost 4 million).

The widespread use of surtitle simultaneous translations has greatly increased interest, and almost every company now uses them.

World premieres continue to rise, with 13 in 1987-88, twice the number from the season before. Premieres were almost unheard of 10 or 15 years ago, but they are now done by the most traditional companies.

On the down side, more than half of U.S. opera companies operated in the red in 1987-88. (Utah Opera is among the fortunate companies showing black ink.)

- FROM NEWSPAPERING TO NUDITY: that's the progress of John Cowles Jr., who gave up running his family's media empire and now upon occasion dances naked with the Bill T. Jones-Arnie Zane Dance Company.

Time was (before 1983) when Cowles ran the Cowles Media Co., and published the Minneapolis Star and Tribune. After he left the helm of his company he pursued "other interests," such as agricultural economy and aerobic dancing, becoming an aerobic dance instructor at the Sweatshop in St. Paul.

A year ago he was smitten with the idea of performing. When he and his wife, Sage, a former professional dancer, tried out for the Jones-Zane company they were both accepted. The piece they dance in is "The Last Supper (etc.)," a three-hour avant-garde work that "begins with slavery in America and ends with a flower-power manifesto . . . an apotheosis in the buff," said a New York Times review. Cowles suggests that the nudity is a metaphor for getting rid of the unimportant barriers between people.

John Cowles III, who now heads Cowles Media, is perhaps the least surprised by the turn his parents' lives have taken. "I don't think it was a big leap," he said. "If you go from newspaper work to teaching aerobics, you've gone a pretty long way already." As for what's next, he said, "Who knows?"