Pitch is how high or low a note sounds. In scientific terms this is known as “frequency” which is the number of vibrations per second. A string vibrating at a very low pitch might have a frequency of 25 Herts (vibrations per second), whilst a very high pitch might have a frequency of 2,000 Hz! In musical circles we always associate the words high/low/up/down with pitch but in normal life we sometimes link these words to dynamics (“turn the volume up/down”) which can be quite confusing!