MUSIC REVIEW : Miller Leads Orchestra on Short Notice : The associate conductor of the Los Angeles Philharmonic fills a void, and the musicians respond to his good will and vigor.

With less than six hours’ notice, David Alan Miller, associate conductor of the Los Angeles Philharmonic, stepped in to conduct the Los Angeles Chamber Orchestra in a Mozart program Thursday at the Orange County Performing Arts Center.

Intended as a simple repeat of the previously reviewed LACO concert at Ambassador Auditorium on Wednesday, the program launched the Orange County Philharmonic Society’s ambitious “Mozart Celebration--1991.”

But because outgoing-music director Iona Brown had developed a sudden case of severe tendinitis, according to the orchestra’s management, she was forced to withdraw, and a series of last-minute role changes were set in operation, even though the music on the program was unchanged.

Miller accepted the challenge of conducting this chamber orchestra for the first time, anywhere; it must have been a nerve-wracking situation for the 29-year-old, but he rose to the occasion.

Ralph Morrison, LACO concertmaster, took over Brown’s solo duties, and Barry Douglas served as conductor and soloist in the C-major Piano Concerto, K. 503.

Thus, one could expect a hodgepodge of stylistic approaches, and to a large extent, that was what one got.

It would be unreasonable to believe Miller had the time to convey many of his own ideas to the orchestra, but the buoyancy and vigor he brought to the “Paris” Symphony certainly indicated that he had such ideas.

The players responded with a zest and good will that acknowledged his role as hero of the evening. But they also appeared to be observing concertmaster Morrison’s ideas of phrasing and attack.

As soloist in two movements excerpted from the “Haffner” Serenade and the obbligato in “L’amero saro costante” from “Il re pastore,” sung by soprano Evelyn de la Rosa, Morrison offered sweetness of tone and fleetness of finger, but he also maintained a low profile.

As conductor, Douglas managed only to spread his cheerless, prosaic and over-aggressive view of Mozart even wider than he could as soloist.

In the airy and problematic Segerstrom Hall acoustic, La Rosa sounded particularly concerned with beauty of tone at the expense of dramatic expression in the concert aria “Alcandro, lo confesso,” although she negotiated the coloratura demands impressively.