BNC Express


It is essential to grasp the concept of sound and notes. Notes serve as representations of sounds at specific frequencies. Human beings have recognized the necessity to categorize various audible frequencies by assigning them names, much like how streets are named.

However, can a single sound be considered music? No, but when one sound is connected to another, it transforms into music. The music we are familiar with is built upon the tempered system, where the semitone acts as the smallest interval between two notes. Consequently, two semitones constitute one whole tone.

The tempered system delineates the frequency spectrum into octaves, each consisting of seven notes and five alterations, resulting in a total of 12 semitones. In the tempered system, these notes are denoted as C, D, E, F, G, A, and B. On the piano, one octave comprises seven white piano keys (notes) and five black keys (alterations).

7 White Keys + 5 black keys = 12 Semitones = 1 Octave

When we apply an alteration symbol to a note, it results in a shift of one semitone either upward or downward, depending on the symbol used. Using “#” (sharp sign) shifts the note up by one semitone, while using “♭” (flat sign) shifts it down by one semitone.

Notes such as D# and Eb are referred to as enharmonic; when played on a piano, these two notes produce the same sound (similarly, G# and Ab share this characteristic). It’s essentially a matter of perspective. The piano stands as the sole instrument capable of reproducing all the notes within the tempered system.

A piano consists of 88 keys, encompassing seven full octaves with two additional partial octaves on either side. These octaves are numbered from 0 to 8, meaning that, for instance, C2 represents the C key within the second octave of the piano.


A scale is a set of notes selected in a specific sequence. For instance, all the notes connected by one semitone create the chromatic scale.
If these notes are played at a distance of:

T T sT T T T sT we obtain the major diatonic scale and it sounds like this

T sT T T sT T T we obtain the minor diatonic scale and it sounds like this

The eight notes of the scale are called degrees and every degree has a different name.