Chord is a concept that can be used as an adjective or as a noun. In the first case, the term chord qualifies that which corresponds to something or is concordant.
For example: “The medical team found that 70% of the town’s children do not have a weight according to their age”, “We need to hire employees according to the company’s profile”, “I do not think that I am receiving a salary according to the obligations assigned to me ”.
Suppose an international soccer tournament is held for players under the age of 18. Of the ten participating teams, nine have rosters made up of soccer players between the ages of 16 and 18. The tenth team, instead, decides to attend the competition with players as young as 13. Given this situation, it can be said that this team would not have led a team according to the magnitude or the demands of the tournament, since it would be at a clear disadvantage compared to its rivals.
As a noun, chord is the name given to the set of various sounds that are harmonically combined. In other words: the chord is formed with different musical notes, which sound simultaneously and in harmony.
Chords are usually made up of between three and seven musical notes. The various chords that are part of a composition create a harmonic progression. The songs, in this way, present different harmonic progressions.
It is important to note that there are musical instruments with which you cannot create chords. One of them is the drum which, due to its characteristics, prevents two or more notes from being played simultaneously.
At the other end is the piano, with which it is possible to play individual chords and notes simultaneously, in addition to applying different styles to the performance. This instrument allows a very high degree of expressiveness to be achieved, as well as being highly versatile: it can be used as a single instrument, to accompany a singer or as part of a varied number orchestra, and it never seems to be at a disadvantage.
The guitar is another instrument in which chords and melodies can be played; however, it does not allow the simultaneous execution of as many notes as the piano because the musician does not have his ten fingers for this purpose. It is the most popular instrument in the western world, since it is not necessary to have great knowledge to play a simple accompaniment. This does not mean that it has little potential; on the contrary, the most difficult concerts can only be performed by the great guitarists.
In this context, especially among guitar aficionados, it is not uncommon to hear the word note to refer to a chord. It goes without saying that this is not correct, since they are two different concepts, as explained above. The source of the confusion surely lies in the fact that they share the first half of their name, as with the C major chord and the C sharp note.
To compose a song, it is necessary to choose a key, that is, a certain organization of the hierarchy that exists between the heights of the sounds, according to the sound consonance with reference to the so-called tonic, which represents the note, the chord and the diatonic scale principal. For example, the tonic of the minor is, in effect, the note la, and the chord of the tonic is the minor; Its scale is characterized by coinciding with the white keys of the piano, like C major.
Musicians’ ears automatically adapt to each key, and this allows them to avoid those notes and chords that are not part of it; for example, in A minor, it is not possible to play the sharp note, unless it is an accident duly indicated in the score, which has a defined purpose, such as modulation to another key.