Classical music and slow music
Means by the terms of classical music all Western music wise, as opposed to popular music from the Renaissance to the present day. More specifically, the term also refers to the current classical music written between the death of Johann Sebastian Bach (1750) and the advent of Romanticism in the 1820.
Classical music, folk music and slow music
The border that demarcates the classical music of the so-called popular music is sometimes very thin. First, Renaissance music (classical) takes as its sources of Gregorian chant as the music of troubadours and medieval. Conversely, the variety of music of the twentieth century is based mostly on the tonal system, introduced by the baroque to the dawn of the seventeenth century. The connections between the two main families of European music are many, which makes it all the more nebulous term of classical music. In addition, the term classical music (music that deserves to be emulated) underlying the concept of repertoire, before the nineteenth century, is simply anachronistic.
Composers and interpreters
This is probably the concept of repertoire that differentiates most likely classical music to folk music, and since the beginning of the Renaissance. The musical tradition learned differentiates the interpreter of the composer who wrote his works not only for him, but possibly also (and sometimes exclusively) for other musicians, then vectors themselves to the listener. Popular music would be rooted in its time, but did not survive, while classical music is designed to withstand the test of time through generations of performers. Classical music would therefore that Nicholas Cook called a "capital aesthetics", i.e. a directory, by the distinction between performer and composer, while popular music is written for and or a musician or a group of musicians for himself.