Denis Noble is a cardiac physiologist and is one of the pioneers of systems biology, having formulated the first mathematical model of the heart in 1960. He is also a philosopher of biology, and his book The Music of Life challenges the foundations of current biological sciences, questions the central dogma, its unidirectional view of information flow, and its imposition of a bottom-up methodology for research in the life sciences. The Music of Life examines some of the basic aspects of systems biology, and is critical of the ideas of genetic determinism and genetic reductionism. He points out that there are many examples of feedback loops and "downward causation" in biology, and that it is not reasonable to privilege one level of understanding over all others. He also explains that genes in fact work in groups and systems, so that the genome is more like a set of organ pipes than a "blueprint for life". He plays classical guitar and sings Occitan troubadour and folk songs. He was a founder of the music group The Oxford Trobadors. He is currently working on a book that will be the successor to The Music of Life.