The extended San Francisco Opera family is gathering to bid a tearful, but music-filled, farewell Monday afternoon to one of its beloved members, the late mezzo-soprano Zheng Cao, who died in February at age 46 after a five-year, hard-fought battle with lung cancer.

Born in Shanghai during the Cultural Revolution, Cao emigrated to the United States in 1988 with very few resources, except her considerable vocal gifts and her generous personality and made her way into some of the leading opera companies of the world. An alumna of both the Merola and Adler Fellow apprenticeships at San Francisco Opera, the singer was based here and appeared many times with the company, most notably in a starring role in the world premiere of Amy Tan and Stewart Wallace's "The Bonesetter's Daughter" in 2008. Her other roles, all warmly received, included Cherubino in "Le Nozze di Figaro," Nicklausse in "Les Contes d' Hoffmann" and an especially appealing Suzuki in "Madama Butterfly." Last year, the Merola Opera Program established an opera fund in her name, which goes to support either an incoming mezzo-soprano or an artist from Asia Pacific.

Among her many friends, Cao counted as some of her closest the novelist Tan and fellow beloved Bay Area mezzo Frederica von Stade, both of whom will be present and contributing at the memorial concert and readings from 3 to 5 p.m. at War Memorial Opera House. Sopranos Nicolle Foland and Patricia Racette, San Francisco composer Jake Heggie and the renowned Bay Area cellist Emil Miland are among the other presenters, as are singers from Susan McMane's new Young Women's Choral Project. The program will encompass arias, instrumental pieces, Chinese folk songs and art songs and a video tribute with input from Cao's family and friends. The public is invited to attend the free event and requested to wear red accessories or attire.

SHE'S PRETTY FAIR ON THE THEREMIN: The San Francisco Symphony is winding up its subscription season in early July -- and if you're not already clutching one of those precious tickets to its gangbuster closeout, Leonard Bernstein's "West Side Story," in full concert version, I'm sorry to say you probably won't be there. But there is still time to grab a ticket to the last concert on the Chamber Series, which spotlights the talents of the Symphony's own estimable players and is also closing out with something highly unusual. Joining 10 Symphony musicians for Sunday afternoon's concert in Davies Hall will be composer and Boston Conservatory of Music professor Dalit Warshaw, who, we have to warn you, will not really be in touch with her instrument for the occasion. But that's because she composes for, and is expert on, the theremin, that amazing, antennaed electronic device hailing from the late 1920s that produces audible sounds with one human hand waving above it for pitch and the other controlling volume. You've heard it countless times in scary movies and on "The Twilight Zone," but its effects can be ethereal, as well as woodoo-woodoo eerie. Which Warshaw will no doubt demonstrate for you with two of her own compositions, "Transformations," for String Quartet and Theremin and "Nizk'Orah" for Cello, Piano and Theremin. Also on the program is Czech composer Bohuslav Martinu's "Fantasia" for String Quartet, Piano, Oboe and Theremin from 1944, widely considered one of the most prominent pieces for the instrument. There also will be an all-hands-on performance of the Brahms String Quartet in A major to close the performance, which begins at 2 p.m. Tickets, $36, are at 415-864-6000 or www.sfsymphony.org.

HE'S A CELLO FELLOW: Burke Schuchmann, former principal cellist with the Sulzberger Solisten in Austria and the Sacramento Symphony, is the artistic director of the Point Richmond-based Palomarin Chamber Music Foundation, which promotes chamber music education and performances. He has whipped up a little "Cello Heaven" for us -- a "choir" of 10 cellos playing together at 8 p.m. on June 27 at St. Alban's Episcopal Church in Albany. Selections from Villa-Lobos' "Bachianas Brasileires No. 1" are on the program, as are works by Bach, Brahms and Morton Lauridsen. Concert time is 8 p.m. at 1501 Washington Ave. in Albany, and the suggested donation at the door is $20, to benefit the church organ program and the Cello Heaven scholarship program.

Contact Sue Gilmore at sgilmore@bayareanewsgroup.com