Tango

Tango is in 2/4 or 4/4 at 60-110 BPM. The defining instrument is the bandoneón — a 38-button bisonoric concertina, German-built, that produces a reedy, sob-like tone unlike any other free-reed instrument. The classic orquesta típica adds violins (often three or four), piano, and double bass; sometimes a vocalist. Melody and accompaniment shift constantly between staccato ("marcato") and legato ("yumba" or "fraseo") feels; rubato in the soloist's phrases is expected against a steady rhythm section. Harmony is minor-key heavy and uses jazz-influenced extensions in mid-20th-century arrangements. Lyrics, in Argentine Spanish (with lunfardo slang), deal with heartbreak, the docks, gambling, exile, and Buenos Aires itself.

Tango grew in the late 1880s in the working-class neighborhoods and port districts of Buenos Aires and Montevideo, fusing African candombe rhythms, European polka and mazurka, and the milonga (a faster rural song form). By 1910 it had moved from brothels to mainstream Argentine ballrooms, and by the 1920s Carlos Gardel had made it an international song form via Paris recordings and films. The 1940s "golden age" produced the classic orquestas — Aníbal Troilo, Carlos di Sarli, Osvaldo Pugliese, Juan D'Arienzo — each with a distinct rhythmic identity. Astor Piazzolla's nuevo tango from the late 1950s introduced jazz and classical chamber-music techniques, scandalizing traditionalists and eventually being accepted as the genre's modernist branch.

Listen for the bandoneón's tone — a wheezing, vocal quality you can't get from an accordion. The rhythm section alternates between a clipped, marcato "4-on-the-floor" feel (D'Arienzo's signature) and a more elastic, rubato "yumba" feel (Pugliese). Violins frequently slide into notes from below — a portamento that's the genre's most identifiable melodic gesture. In Piazzolla's nuevo tango, the rhythm section uses jazz-style walking bass and the bandoneón takes on a soloist's role.

Carlos Gardel's "Por una Cabeza" (1935) is the most famous classic-era tango. For nuevo tango, Astor Piazzolla's "Libertango" (1974). The album to start with is Piazzolla's Tango: Zero Hour (1986).

The bandoneón was invented in Germany around 1850 by Heinrich Band as a portable substitute for a church organ; it arrived in Buenos Aires with German sailors and immigrants in the late 19th century and was almost entirely absorbed by tango, to the point that German bandoneón production largely existed to supply Argentina.