It is, you can hear it, but I think more of art. An orchestra is an instrumental ensemble, usually fairly large with string, brass, woodwind sections, and possibly a percussion section as well. "Acoustic" as opposed to 'Electronic' or 'Computer Generated' - usually, but not always entirely. An orchestra may include some electronic keyboard and string instruments. And of course, 'orchestra music' may be simulated by sophisticated computer programs.
Ayu-mi-x III Acoustic Orchestra Version was created on 2001-02-28.
Ayu-mi-x II Version Acoustic Orchestra was created on 2000-03-08.
China Film Orchestra Chinese Music Orchestra was created in 1949.
Metal Acoustic Music was created in 1981.
An Evening of Acoustic Music was created in 1996.
There are acoustic, electric, and steel guitars, fiddles, sometimes drums, and violins. For some songs there is an orchestra, with many different strings. There is also, of course, singing.
Acoustic music is non-electrified or amplified. Acoustic music therefore started the first time anyone made music, thousands of years ago.
The orchestra makes ... music.
It is synonymous. Chamber music is the music that is played by a Chamber orchestra.
An orchestra plays music for entertainment/pleasure.
Iranian Orchestra for New Music was created in 1995.
The orchestra played wonderful music in the theatre.