By picking a string, saying a word, or clapping our hands, we create energy transmitted through the particles of matter, the air, for example. When it reaches our eardrums, we hear a sound. This movement of energy has its moments of maximum air pressure - compression and minimum air pressure - rarefaction. Therefore, it is a wave.
A sound wave has characteristics that are inherent in any other type of wave. These characteristics are wavelength, amplitude, and frequency. The duration of a sound depends on its wavelength. The loudness of a sound depends on the amplitude of its wave. The frequency is the number of compression-rarefaction cycles that occur per second. It allows us to distinguish pitches from noise.
Sound waves with specific frequencies are considered musical pitches. The higher pitch has the greater frequency. Systematized pitches have names and symbols called musical notes. Sometimes pitch, tone, and note are used as synonymous. However, you can think of the pitch as the frequency we hear. A note is what we write on the musical staff. And the tone is a complex set of sonic characteristics.
Musical notes have different naming systems. The traditional system:
Do - Re - Mi - Fa - Sol - La - Si
But English-speaking theorists use letters of the Latin alphabet:
C - D - E - F - G - A - B
The same is the case with the designation of the octave from which the note is. In the conservative system, octaves have the following names and designations: sub-contra (AAA BBB), contra (CC BB), great (C B), small (c b), one-line (c1 b1), two-line (c2 b2), three-line (c3 b3), four-line (c4 b4), five-line (c5). In turn, the commonly used system offers to designate octaves with numbers: A0 B0, C1 B1, C2 B2, C3 B3, C4 B4, C5 B5, C6 B6, C7 B7, C8.