Johann Sebastian Bach's main instrument was the organ.
A secondary instrument is a instrument whose sound is in comparison to the main instrument. It also can be a back up instrument.
The main characteristics of a negotiable instrument is that it can be easily regulated.
Johann Sebastian Bach's main instrument was the organ. He was a renowned organist and composer known for his mastery of the instrument and contributions to organ music.
piano
the violin
the fidle
The Hornbostel-Sachs method of instrument classification has 5 main categories, and more than 300 basic groups under those. http://en.wikipedia.org/wiki/Hornbostel-Sachs
The instrument played at the world cup is called a "Vuvuzela"
the saxophone
the piano
classical piano