Sometimes readily accepted as a minimalist and associated with other musicians of his generation, Philipp Glass or Steve Reich, and other times considered an oriented composer who adapts his creative vision to the current socio-political or cultural context and melts in his synthetic creations a multitude of styles, genres and musics, John Adams is indeed the image of the successful contemporary American artist. Not only did he feel constantly challenged to compose scores in all genres, but he combined with overflowing fantasy and rigor of writing effects from such contrasting sound spaces, but with a maximum emotional impact. Our study is aimed at sketching the portrait of the musician, while commenting on some significant scores in the evolution of his composer career.