Americans love miniatures, but do we really need a smaller version of the Pittsburgh Symphony?

The easy answer is that without it we'd miss out on some of the best music ever written for orchestra -- chamber orchestra, that is.

What we think of as orchestras today are large civic or educational institutions, but they didn't start out that way. Orchestras in the 17th century had fewer musicians and less consistency of instrumentation. Over the years, they grew in personnel to accommodate composers' demands and performed in larger halls, eventually becoming too big for earlier music.

By the 20th century, orchestras had become so large -- and so entrenched in performing Romantic music -- that many composers started writing for smaller ensembles again. It all adds up to a raft of repertoire that needs its own platform. That's a gap the Pittsburgh Symphony continues to help fill locally with its Pittsburgh Symphony Chamber Orchestra.

"Vivaldi, Bach, Boccherini, Mozart and many modern, Romantic and impressionist composers wrote smaller-scale works that typically are performed by large ensembles, basically misrepresenting the scale and intent of their works," says Andres Cardenes, PSO concertmaster and conductor of its chamber orchestra. The ensemble has the same high-level musicians when playing venues more suited to a chamber group: Carnegie Music Hall in Oakland and Upper St. Clair High School Theater.

Even when modern orchestras do pare down for a smaller work, such as the PSO does with Mozart concertos, the sound loses some of its intimacy in Heinz Hall.

"We play many works that aren't really aurally optimal at Heinz Hall, such as [Bach's] 'Brandenburg Concertos' and chamber music works that require a smaller ensemble," Cardenes says. "Carnegie Music Hall is a smaller, historical venue, and the musicians are right there -- you can hear them breathe. We can detail repertoire in a very personal and accessible way in smaller-scale works, as you will hear in Vivaldi's 'La stravaganza' violin concertos -- something that easily be lost in large scale [performances]."

Another example comes when the chamber orchestra performs Beethoven's Symphony No. 2 later this season (there are three programs each season) it will be much closer in size to the original orchestra Beethoven used.

There is a world of difference between chamber orchestra works and chamber music, but Cardenes prefers to blur that line with the chamber orchestra, often including octets, sextets and quintets on his programs. "There is a lot of great, interesting chamber music out there that does not get much attention, such as the upcoming Chausson Concerto for Violin, Piano and String Quartet," says Cardenes, adding chamber music "promotes good chemistry, which translates to even better PSO performances."

Cardenes is in his ninth year of programming and conducting the chamber orchestra series, beginning it as Nuance in 1999 at the Jewish Community Center in Squirrel Hill. He has learned much over time.

"I began on a rather conservative platform of baroque music and well-known composers," he says. "We have progressed to the point now where at least one new work is premiered every year and more dramatic and interesting programming is being performed."

Cardenes will conduct the premiere of a new work by composer Evan Premo in March.

He also hopes to collaborate more with local arts groups, such as the Pittsburgh Camerata, which will sing Vivaldi's "Gloria." In the past he has worked with Carnegie Mellon University, where he is a professor of violin, and local composers such as David Stock and Leonardo Balada. "There is a vast talent pool in Pittsburgh to draw upon, so I see many other possibilities looming."

Just don't think of the chamber orchestra as PSO lite -- instead, think PSO magnified.

"It offers a close-up of our musicians and talents."