RARE COPIES of religious music by Mozart and Michael Haydn and songs by Franz Schubert will be returned by the University of California at Berkeley to an Austrian monastery.

The manuscripts, copied by monks in the 18th and 19th centuries, disappeared during World War II during either Nazi or U.S. occupations, from the Benedictine Kremsmuenster monastery near Vienna.The Berkeley campus had acquired them for $1,400 in 1976 from a guard at San Quentin prison, who said he had inherited them six years earlier from a brother-in-law at Fort Sill, Okla. When they were listed in a music library catalog circulated in Europe, an Austrian music expert spotted them and notified the monastery, which requested their return.

- THE ARTS HAVE LOST: Richard Lewis, English tenor, 76, at his home in Eastbourne, England. He sang frequently in opera at Glyndebourne and Covent Garden, and was expert in Baroque and 20th-century music, singing premieres of works by Walton, Stravinsky, Tippett and Schoenberg. He frequently sang concert and opera in the United States as well.

Juan Matteucci, Italian-born Chilean conductor, died of heart trouble at 70 in Auckland, New Zealand. His many worldwide appointments included permanent conductor of the Santiago Philharmonic and many tours as a guest conductor of American and European orchestras. Matteucci will be remembered in Utah, where he conducted the Utah Opera in its first seasons.

Drummer Art Blakey, longtime leader of the Jazz Messengers and a giant of modern jazz, died at 71 in New York, of lung cancer.