Instrument factors

All stringed instruments have up to six factors which must be maintained to make good music. If you can get these principles into your head, you'll have it in a nut shell ;-)
1. A frame- Whether a violin or a piano, this holds the beast together as a unit so that it can be used over and over.
2. Strings- These vibrate and generate the tones.
3. Tension- This is set so that the instrument agrees with music theory and so that the volume is agreeable. The trick is to keep from rupturing the whole thing. An average piano holds up to 12 tons of tension.
4. Some way to agitate the strings- Whether hammers, a bow, or your "lil ol fangers."
5. Most stringed instruments have a box or sound board to amplify the sound.
6. Ornamentation- Esthetics in appearance demand a tassel from an Ethiopian masenko, engraving on a silver flute, and an expensive glossy finish on a piano. This factor has nothing to do with sound, but I defy you to find me a musical instrument that has not added esthetics. It points to the fact that making music is an art form.
A piano tuner's job security lies in the fact that all this tension in the instrument