From Latin modulatio, the term modulation is related to the fact and consequences of modular. This verb has several applications and uses, such as altering the properties of a sound, changing the factors that affect a procedure to achieve different results, leaving one key to appeal to another, or modifying the value of one. frequency, phase or amplitude of a wave.
For the telecommunications, the modulation are those techniques applied in the transport of data on carrier waves. Thanks to these techniques, it is possible to take advantage of the communication channel in the best way to transmit a greater flow of data simultaneously. Modulation helps protect the signal from interference and noise.
The modulation process consists of varying a parameter that is in the carrier wave as a function of the alterations in the modulating signal. It can be spoken of frequency modulation, amplitude modulation, base modulation and wavelength modulation, among other types.
In the musical field, modulation consists of alter tonality momentarily, for which it should not be indicated in the score with a new key signature, and it is possible to resolve by means of a cadence, although it is not mandatory. In general, the aim is to move to close keys (not to be confused with the physical proximity of the notes on a staff, but rather that they are related in some direct way and that require the least amount of changes or «accidents»Starting from the main one), although sometimes it is sought to change the mode (from higher to lower or vice versa) or at different intervals.
The three types of modulation currently considered are explained below:
* using a bridge chord: when it comes to shades neighbors, according to what was explained in the previous paragraph. The idea is to start from a chord common to both keys, and then perform a cadence to resolve at the desired destination. The simplest case, that is, the one for which no alteration is needed, is to go from a key to its relative minor or major, such as from C major to A minor. On the other hand, the most complex is to modulate to a tone that shares only one chord with the original.
* by chromaticism: consists of starting from a chord of the main key and altering a note chromatically (raising or lowering half a tone) to convert it into a chord of a new key, which was not related to the first. If, for example, you want to go from C major to G minor (it should be noted that the G major chord with its minor seventh is the dominant of C, which means that it occupies an essential role in that key, since there is a lot of tension between this and C, the tonic) it is possible to take a G Major chord and then convert the B natural (also called natural) in flat.
* enharmonic: it is obtained when the way of writing one or more notes of a chord is altered, although they continue to produce the same sounds. A practical example is writing Sustained sun What A flat that, leaving aside the particular appreciations of some string musicians, they should produce the same amount of vibrations, so that the ear cannot perceive a difference. Musically, the distance between two keys involved in this type of modulation is very large.
Finally, the voice modulation refers to the alteration of tone with harmony and smoothness, that is, without standing out to the listener’s ears. The announcers and actors must be trained to modulate the voice according to the genre that they transit, without losing clarity in expression or elegance.