Members of the oboe section of the St Louis Civic Orchestra:
Bob Herman (Principal), Heather Schier and Marcus Raichle (English horn).
The instruments that are customarily found the oboe section of most symphony orchestras include the oboe (right)
and the English horn (center).  These two instruments represent the soprano and tenor voices of the section.
Less commonly seen is the oboe d'amore, the alto member of the section. The oboe d'amore is frequently used
in baroque music, particularly that of Bach.  On rare occasions a bass oboe is employed which looks similar to the
English horn but is longer.  It's voice is an octave lower  than the oboe.