How do Composers Write Music That Makes us Think of CertainCharacteristics?

Different musical instruments can make people feel different kinds of ways. For example the violin is happy and percussion makes the music feel angry or strong. What makes songs sad? Apart from the lyrics, it's because the melody mostly features a musical construct called the minor third, which musicians have used to express sadness since at least the 17th century. The minor third's emotional sway is closely related to the popular idea that, at least for Western music, songs written in a major key are more happy, while those in a minor key are more sad.

- The flute or some other woodwinds sound romantic.
- The violin or viola, as i said before, is happy.
- And percussion make the music sound strong or angry.
- The oboe or cello will sound sad and/or slow paced.

References:
http://www.theatlantic.com/entertainment/archive/2010/12/what-makes-a-song-sad/67709/