There’s a physical explanation for each and every sound which is generated from a musical instrument, be it a piano, guitar, cello, or any other musical instrument. The resultant sound depends on several things, two main factors being the way in which the instrument in question has been created and the kind of materials that have been used for its making.
As you might have learned in your A level Physics Tuition classes, there’s no matter implied in a sound wave, which, in simplest yet practical terms, can be defined as a transfer of energy. This is an accurate description of sound wave. If you want to keep your approach theoretical, you can define sound wave as a mechanical longitudinal wave.
While many don’t think about this but the fact of the matter, which is fully evident if you give the matter a moment’s thought, is that there’s a strong, one can say even an intimate, relation between a musical instrument (this includes every type) and Physics. Are you wondering how these two coexist?
Well, this is a fair question. You see there’s a specific mathematical formula which explains music. As you might know every sound has a wavelength, which is the distance between consecutive crests of a wave, specifically two points in a sound wave where sound doesn’t exhibit repeated behavior. The smallest interval in which there’s no repetition of wave behavior is termed as period, denoted by ‘T’. You might have also come across a term called frequency, which in terms of sound waves can be simply defined as the number of times sound vibrates in 1 second.
The wavelength as well as frequency of a sound wave determines its speed. A musical instrument can create a range of sounds all travelling at different speeds. If the talk is on the relation between Physics and musical instrument, one has to include one specific topic and that topic is interference. The possibility of two sounds being present at one place at the same time cannot be ruled out. As a matter of fact, this possibility is quite high. What kind of effect combined waves produce can be better examined and understood with the help of Superposition theory.
Here’s an example to explain in simpler terms. Let’s say two musical instruments which are identical in every way (let’s assume these two instruments are trumpet) are blown simultaneously at a specific frequency. The resultant sound is not likely to be positive and might even result in headache. The resultant sound produced when crest of 2 different waves meet is not pleasant. This phenomenon is termed as destructive interference.
Additionally, one can say with certainty that both waves will finally return to their initial form. While majority of people don’t have any clue whatsoever about how music is created, this knowledge is absolutely crucial for people who make musical instruments.
Another aspect, which in fact is most relevant, as you might have gathered from your physics tuition teacher, is sound intensity. This is a big of the relationship between physics and music instruments.