What are Pitches?

Now we know how much a wide variety of pitches can help the sound of music. But what exactly is pitch? We know that musicians can produce both high and low notes, but how exactly does it work? Well, remember what we discussed in Lesson 1? Sound is simply vibrations of air. We've established that there is an infinite variety of vibration possible, creating an infinite variety of sound. But that still doesn't answer our question of "What are Pitches?".

Well, consider this: the main chamber music instruments all have strings, right? Well, a string instrument player can raise the pitch of his/her instrument by moving his/her fingers to shorten the string! A pianist can raise the pitch of his/her instrument by playing a key connected to a shorter string! So, a shorter string must cause a higher pitch, and a longer string must cause a lower pitch! Maybe you've tried this with a rubber band before: if you pinch off the rubber band and pluck it, it will vibrate; causing a high pitch to occur. If you don't pinch the rubber band and just pluck the entire band, it will vibrate and cause a lower pitch to occur. This works in the same principle as the chamber music instruments

Great! Now we know how to create a higher or lower pitch. But what exactly is happening? Well, every time a musician plays a note, his or her string is vibrated very rapidly. In other words, the string moves back and forth almost inconceivably fast (the violin's A string vibrates at 440 times per second!). A longer string will vibrate more slowly than a shorter string. Perhaps you've experienced this with a jump rope. A single person jumping rope can get his/her rope to go very quickly. This is similar to the vibration of a short string. A jump rope held by two people standing far away will not travel nearly as quickly as the single person's jump rope. This is similar to the vibration of a long string. So, fast vibrations must correspond to higher pitches, and slow vibrations must correspond to lower pitches.