Classical Concert

Internationally known Korean American pianist Seung-Un Ha will make her debut with the Los Angeles Chamber Orchestra this weekend in Glendale. Ha first performed at New York’s Lincoln Center in 1989 and made her Los Angeles Philharmonic debut in 1998. She has performed throughout the country and in Germany, France, Scotland, Mexico, Brazil and Taiwan. Ha will play Mozart’s Piano Concerto No. 25. Saturday’s program also includes Lutoslawski’s Dance Preludes, featuring clarinetist Gary Gray.

* Los Angeles Chamber Orchestra; Saturday, 8 p.m.; Alex Theatre, 216 N. Brand Blvd., Glendale. $13-$53. (213) 622-7001, Ext. 215.

Stamp Show

The International Stamp Collectors Society presents its Stamp Expo/Valley this weekend in Encino.

* Stamp Expo/Valley; Friday, 11 a.m.-6 p.m.; Saturday, 10 a.m.-6 p.m.; and Sunday, 10 a.m.-5 p.m.; St. Nicholas Community Center, 17114 Ventura Blvd., Encino. Free. (818) 997-6496.

Opera

The Valley Symphony Orchestra presents a semi-staged but fully costumed production of Verdi’s “La Traviata” on Saturday at Valley College. Robert Chauls will conduct.

* “La Traviata”; Saturday, 8 p.m.; Valley College, 5800 Fulton Ave., Valley Glen. $10-$15. (818) 947-2346.

Celtic Music

The Celtic Arts Center will present an afternoon of music and dance Sunday at its new digs in Valley Village. The program will feature the Everything Celtic dance troupe and the band Highland Sun.

* Everything Celtic and Highland Sun; Sunday, 3:30 p.m.; Celtic Arts Center, 4843 Laurel Canyon Blvd., Valley Village. $8-$10. (818) 752-3488.

Jazz Concert

Famed jazz musician Charlie Haden will perform Tuesday with his Liberation Music Orchestra in the Main Gallery at California Institute of the Arts. Haden won the 1998 Grammy for best instrumental jazz performance for his recording “Beyond the Missouri Sky” with Pat Metheny. Haden can be heard on more than 300 albums made with such jazz greats as John Coltrane, Ornette Coleman, Joe Henderson and Keith Jarrett.

* Charlie Haden’s Liberation Music Orchestra; Tuesday, 8 p.m.; Main Gallery, CalArts, 24700 McBean Parkway, Valencia. Free. (661) 253-7832.