Classical music refers to the whole range of Western scholarly music of liturgical and secular origin, as opposed to popular music, for the general public, from medieval music to the present day. From a musicological point of view, the adjective classical refers to the music of the classical period written between the mid-18th century and the advent of romantic music in the 1820s. Another way of defining this type of music is to evoke the written tradition, which is less present or completely absent in popular music. Scholarly music is generally transmitted through the written word (the score), popular music is most often transmitted through the spoken word.
The borderline between classical or scholarly, popular music is sometimes thin. First of all, Renaissance music draws its sources both from Gregorian chant and from the secular music of medieval troubadours and trouvadours (all nobles first, then "bourgeois", enlightened, cultivated, and thus practicing an art of composition not so popular as that; not to be confused with "minstrels", popular travelling musicians, trained in the many schools of "menestrandie", ancestors of the current academies and conservatories): from the beginning, the distinction between "popular" and "learned" is complex. Conversely, 20th century variety music is largely based on the tonal system, gradually introduced from baroque music at the dawn of the 17th century, and on the temperate scale (late 18th century). There are therefore many connections between the two great families of European music, which makes the term classical music all the more vague.
The contribution of classical music to popular music is no less important. The various popular musics are generally linked in some way to a part of the classical repertoire, even if these influences are very rarely claimed. In the same way, so-called classical music also borrows a lot from popular timbres.
This distinction is sometimes seen as social (classical comes from the Latin classicus meaning "first-class citizen") - this category would not describe the music itself, but those who listen to it. According to a musicologist, Régis Chesneau, this category would not describe an aesthetic but social contingencies.