 This innovation a key step in the process of evolution of the danzón, which over the years had progressively lost its structural rigidity to the benefit of musicians and dancers alike.Prior to the "danzón de nuevo ritmo", in 1910, José Urfé had first added a montuno (typical son improvised closing section) as a final part of his composition "El bombín de Barreto".This was a swinging section consisting of a repeated musical phrase, which introduced some elements of the son into the danzón.