The essence of tango dancing is addressed in this intriguing book: milongas, the head nod, dance styles, dress code, improvisation styles, different rhythms. But, in addition to dance, this book covers many other aspects of the genre, such as, for example, those relating to music: from the indisputable characters --such as Astor Piazzolla and Carlos Gardel-- to the bandoneon, the typical orchestra and the so-called 2 x 4 rhythm, which erroneously describes tango. Moreover, tango keys, that is, those "keys" that open a huge and varied universe include those places where the genre was or is alive and present, such as bars, neighborhoods, the carnival or the city of Buenos Aires itself. The tango lyrics and the poets who wrote them have their own keys because it must be remembered that a large part of those lyrics is genuine popular poetry that covers all imaginable topics: finding and losing love, suffering, loneliness, disappointment. Also, the neighborhood, horses races (great tango theme!), cafés, friendship, soccer, courage, work, social claim, carnival, the port, the sea, alcohol, landscapes, smoking and - believe it or not- overweight issues, as in "Gorda" (in Spanish "fat"), 1928.