Milonga can refer to an Argentine, Uruguayan, and Southern Brazilian form of music which preceded the tango and the dance form which accompanies it, or to the term for places or events where the tango or Milonga are danced (see Milonga (place)). The term milonga comes from a similar expression that means "lyrics".

The Milonga originated in the Río de la Plata area of Argentina and Uruguay. It was very popular in the 1870s. The Milonga was derived from an earlier style of singing known as the payada de contrapunto. The song was set to a lively 2/4 tempo, as are most milongas.

"Milonga is an excited habanera." The original habanera divided into four pulses, in a standard two-four where every note was stressed. In becoming milonga, though, all four notes turned strong, as tempo was doubled. The strength of the first beat weakened the fourth giving an almost waltz-like feel to milonga: one-two-three(four), one-two-three(four). Habanera is a slower, more explicit sounding one, two, three-four. At least one modern tango pianist believes the polka influenced the speeding up of the milonga.

Music is an art form whose medium is sound and silence. Its common elements are pitch (which governs melody and harmony), rhythm (and its associated concepts tempo, meter, and articulation), dynamics, and the sonic qualities of timbre and texture. The word derives from Greek μουσική (mousike; "art of the Muses").

The creation, performance, significance, and even the definition of music vary according to culture and social context. Music ranges from strictly organized compositions (and their recreation in performance), through improvisational music to aleatoric forms. Music can be divided into genres and subgenres, although the dividing lines and relationships between music genres are often subtle, sometimes open to individual interpretation, and occasionally controversial. Within "the arts", music may be classified as a performing art, a fine art, and auditory art. There is also a strong connection between music and mathematics.

To many people in many cultures, music is an important part of their way of life. Ancient Greek and Indian philosophers defined music as tones ordered horizontally as melodies and vertically as harmonies. Common sayings such as "the harmony of the spheres" and "it is music to my ears" point to the notion that music is often ordered and pleasant to listen to. However, 20th-century composer John Cage thought that any sound can be music, saying, for example, "There is no noise, only sound." Musicologist Jean-Jacques Nattiez summarizes the relativist, post-modern viewpoint: "The border between music and noise is always culturally defined—which implies that, even within a single society, this border does not always pass through the same place; in short, there is rarely a consensus ... By all accounts there is no single and intercultural universal concept defining what music might be."