Do you ever wonder why the oboe tunes the orchestra?! In the late 1600s, orchestras were comprised of mostly string instruments. Two oboes were sometimes used to boost the first and second violin parts. Soon composers were writing separate parts for the oboe, showing off its beautiful singing tone as a contrast to the violins. The bright, rather penetrating sound of the oboe was easy to hear, and its pitch was more stable than gut strings, so it was the obvious choice for reliable tuning. Other instruments were used in on occasion in the orchestra at that time – flutes, bassoons, French horns, clarinets – before its instrumentation became relatively standardized as we know it today. But oboes were almost always present, so they became the standard instrument for tuning.
Orchestras always tune to ‘A’, because every string instrument has an ‘A’ string. The standard pitch in the United States is A=440 Hertz (440 vibrations per second). European orchestras favor a slightly higher pitch – A=442 or higher.
Now here is a little known secret that the audience may not know – oboes can play sharp or flat, just like any other instrument, but every oboist uses a little electronic meter to ensure that their ‘A’ is exactly right.