After the success of his operas up to and including Madama Butterfly, Puccini could afford to spend more time in choosing subjects which were different in style and form from anything he had already written. His mid- to late-period operas are, in consequence, amongst his most innovative. The fruits of this artistic freedom include the semi-operetta La rondine, the trilogy of contrasting one-acters Il trittico, and the depiction of the California gold rush, La fanciulla del West (The Girl of the Golden West).