There are several questions musicians ask themselves in the process of listening,
:performing or composing music

-How does our ear perceive the expressive meaning of pitch structures in a musical

-?How can our musical hearing and thinking work in performance or composition

-What are “tension” and “relaxation” and how are they expressed in a defined musical

-? How can we build, measure and control the expressivity of music

-? How can theoretical knowledge be translated into expressivity of sound structures

-What, why and how do we develop musical hearing concomitantly with musical
? thinking

-?How can we “make” the music “alive” and what is the role of musical inner hearing

More questions and problems appear in musical practice.
One of the essential questions is:
what is the meaning of the pitch structures we listen to or produce
.Answers are usually given in the range of theoretical-grammatical notions.
The main matter is not how pitch structures are defined theoretically, but how they are
..expressed in a musical language

Among many different activities, musicians perform, compose, research and/or listen to music. All these activities are related to producing or identifying sound structures created in the frame of a determined musical language.
?For example, let us ask ourselves what is the right intonation of a major second
To give an appropriate answer, we must know what causes the feeling of musical tension .between the two pitches of that interval
The tension created between the two pitches of a major second are defined and perceived differently in various musical languages for instance in a non-tonal musical language versus
. the tonal musical language
That means the criteria establishing theoretically and expressively a major second, its perception and production differ because of the different meanings it has in various musical languages.