The Napa Valley Symphony Orchestra’s mid-winter programs this weekend in Yountville’s Lincoln Theater have been scaled back to a chamber music concert.

Two additional guest artists — acclaimed 25-year-old pianist Orion Weiss and Carla Maria Rodrigues, principal violist with the San Francisco Opera Orchestra — will join the already announced headliners, cellist Zuill Bailey and violinist Giora Schmidt, in a program that will also feature a trio of seasoned players from the Napa Valley Symphony Orchestra playing the music of Tchaikovsky, Handel and Brahms.

The full orchestra, under the baton of music director Asher Raboy, will return to the Lincoln Theater stage for a pair of concerts in March, said Richard Aldag, general manager of the Napa Valley Symphony Association.

It’s no secret that the association has been going through some belt-tightening in order to weather financial problems encountered a few years ago.

“We decided to refocus the (February) concert in order to get back on track financially,” Aldag advised. “Ticket sales are not where they should be and we needed some breathing room.”

Aldag met with both players committee and representatives from the musicians union to reach consensus on changing the program from one with full orchestra to one featuring chamber ensembles.

“We agreed this was the best way to catch up (financially),” he added, “to transform this concert and move ahead with the rest of the season as planned.

“We felt our audiences would understand ... (that we needed) to put our financial house in order rather than cancel a concert.”

The program for the pair of concerts (Saturday at 8 p.m. and Sunday at 3 p.m.) will feature Bailey, Schmidt, Rodrigues and Weiss in a performance of Brahms “Piano Quartet No. 3 in C Minor (Op. 60),” as well as Schmidt and Bailey playing a transcription of a Handel “Passacaglia” originally composed for keyboard.

The three guest string players will team up with the three members of the Napa Valley Symphony Orchestra to perform Tchaikovsky’s “Souvenir de Florence.”

“This will give our audience an opportunity to hear our players in a different context,” Aldag added.

He was also enthused about having up-and-coming young pianist Orion Weiss on the bill, making his Napa Valley concert debut.

In commemoration of the its 75th Anniversary Season, the Napa Valley Symphony is offering a special “mini-subscription” for the remaining concerts of its 2007-2008 Classical Series. Patrons will be able to purchase the best tickets available for the remaining three Saturday night concerts for $75, a savings of $105 over regular pricing.

Tickets — either mini-series or for one of the two weekend performances — may be purchased by calling 226-8742.