Character of the Music and the Dance
Argentine Tango is a very close dance. It has precise foot work that is lead/followed through pinpoint body movements. It is danced in place or around a room. It is often emotionally connected to a love and hate dynamic enhanced with flirtation.
Guitar, Bandoneón (or Accordian), Piano, Violin, Flute, Double bass
The back beat is either created by a drum roll in the back ground Boom-Boom-Boom--Roll. Or its created by an instrument like the violin going Boom-Boom-Boom-Boom
Click the Samples Below
There is a mix of all the common instruments in this song that would would expect of a Tango. Drum Rolls, Violins, Bandoneon, and more.
The Drum Roll and violins do a great job of creating a back beat however the Bandoneon adds a really nice touch of flavor to the song.
The drum rolling in the songs is very soft, so the Violin tend to help create the main beat to the music. It is not uncommon for the Violin to take over the back beat when there is no Drum rolling at all.
More modern styles of Argentine Tango music tend to take out the drum rolling all together. Instead they use the more Common Boom---Tick beats complimented with Tango Embellishments.