After seeing an ad on TV for an upcoming event, I was wondering: What’s the difference between different kinds of orchestras? The types I can think of off the top of my head are symphony, philharmonic and chamber - are there any other kinds that I’m missing? Are there specific requirements to be able to call yourself a particular type of orchestra, or is it just what you feel like being called?
I belong to various groups that use all three of the designations.
I am not aware of any practical distinction between a Symphony and a Philharmonic. They seem interchangeable, although there may be some official difference. Invariably a medium-to-large-sized group of musicians.
A Chamber Orchestra, on the other hand, is definitely a smaller, more intimate assembly.
A quick count of the number of 1st violin players may give you a good indication. 4 or more stands (8 players) is probably going to be called a Symphony Orchestra. Under that could go by any of the three names.
Chamber orchestras are generally smaller than “full-blown” orchestras, although exceptions can probably be found if one digs hard enough. For example, the Los Angeles Chamber Orchestra maintains a pretty small roster - look at their group photo on this page on their website.
As for the other types, it’s pretty much whatever an orchestra wants to call itself. In the US, the most common naming scheme is the XXX Symphony Orchestra. However, the Los Angeles Philharmonic, the New York Philharmonic, and the Philadelphia Orchestra (to name a few) all buck that trend. Differences between those groups and, say, the Chicago Symphony Orchestra are negligible in terms of composition, typical repertoire, etc. These big groups tend to be bigger, although they can easily play the material from the “chamber orchestra” realm by simply paring themselves down.
As an afterthought, you may find that Philharmonic is used more for the names of major metropolitan orchestras, not usually your garden-variety community symphony. Certainly many exceptions to this, though.
Chamber orchestras will usually have smaller string sections, and few or no brass and percussion. There are other types of chamber ensembles, but they tend not to use the designation “orchestra”.
This is, of course, a pretty broad generalization.