If we were to categorise this traditional tango, we would have to talk about this spontaneous improvisation, this dialogue between the instrumentalists within a harmonic and melodic tapestry. Because it is indeed this art of dialogue that the Fukui-Jallu duet initiated. It is also the result of a desire to bring the music of the guitarist Roberto Grela (1913-1992) back to life, accompanied by Anibal Troilo. This famous duet marked its era by the harmonic richness of R. Grela and A. Troilo's art of phrasing.