The term ORCH. SECTION is a musical term referring to the orchestra section of an ensemble. The acronym STR (3 letters) stands for strings, which are the bowed string instruments such as the violin, viola, cello, and double bass. OFO (3 letters) stands for other instruments, which are the non-string instruments such as the flute, oboe, clarinet, and bassoon. PERC (4 letters) stands for percussion, which are the instruments that produce sound by being struck, shaken, or scraped such as the timpani, xylophone, and snare drum. STRS (4 letters) stands for string section, which is a group of string instruments playing together in an orchestra.