Argentine tango is a musical genre of simple quadruple metre and binary musical form, and the social dance that accompanies it. Its lyrics and music are marked by nostalgia, expressed through melodic instruments including the bandoneón. Originating at the ending of the 19th century in the suburbs of Buenos Aires, and Montevideo, Uruguay, it quickly grew in popularity and spread internationally. Among its leading figures are the singer and songwriter Carlos Gardel and composers/performers Francisco Canaro, Juan D'Arienzo, Osvaldo Pugliese, and Ástor Piazzolla.