THE ARTS HAVE LOST: Boris Christoff, 79, Bulgarian bass, in Rome, from effects of a stroke he suffered six years ago. He excelled as Boris Godounov, King Philip II, Mephistopheles and in similar roles requiring Russian power and dark-hued tone. A prominent basso of almost every international opera house, he somehow never sang at the Met . . . Manuel Alum, 50, modern dancer and choreographer, of cancer, in Manhattan. He trained with Martha Graham, danced with Paul Sanasardo, before forming his own company in 1971 . . . Soprano Arleen Auger, 53, of brain cancer, in Amsterdam. A late bloomer, Auger made her debut at the Vienna State Opera as Queen of the Night, her one role at the time, without a rehearsal. She became a sustaining singer there, and in many European houses, appearing little in her native America. Her discography in opera and song is varied and extensive.
- THE COLORADO DANCE FESTIVAL, at Colorado University in Boulder July 8-31, will offer an interesting slate of public concerts. These include Contraband, July 8-11; Stephen Petronio Company July 16 and 17; Eiko & Koma, July 22-24; Rachel Rosenthal, July 26-27, and GhettOriginal Productions Dance Company, July 31. For ticket or general information, call (303) 442-7669, or write Colorado Dance Festival, P.O. Box 356, Boulder, CO 80306-0356.- "PACIFIC VISIONS," a program to maintain the vitality of the opera repertoire through new opera commissions, has been launched by San Francisco Opera, with Lotfi Mansouri as artistic director. The program is being launched with the commissioning of two new operas: "The Dangerous Liaisons," by Conrad Susa; and an opera with the working title "Gethsemane," to be composed by Bobby McFerrin to a libretto by Ishmael Reed.
- STEPHANIE REINHART has been appointed co-director of the American Dance Festival in Durham, N.C. She shares the posit with her husband, Charles L. Reinhart, festival director since 1969.