The city is divided into ''barrios'' (neighborhoods) for administrative purposes, a division originally based on Catholic ''parroquias'' (parishes). A common expression is that of the ''Cien barrios porteños'' ("One hundred ''porteño'' neighborhoods"), referring to a composition made popular in the 1940s by tango singer Alberto Castillo; however, Buenos Aires only consists of 48 official ''barrios''. There are several subdivisions of these districts, some with a long history and others that are the product of a real estate invention. A notable example is Palermo – the city's largest district – which has been subdivided into various ''barrios'', including Palermo Soho, Palermo Hollywood, Las Cañitas and Palermo viejo, among others. A newer scheme has divided the city into 15 ''comunas'' (communes).