Few things in life are more ubiquitous than the institution of music; indeed, not only is music present in our natural surroundings (and no, I'm not speaking of radio waves constantly passing through our bodies, though, undoubtedly, it is the case,) but it is easily the most implemented and explored social form of entertainment.
Music as natural form is far too often dismissed -- not by great thinkers, but by the common folk -- which is not to say that they are necessarily wrong, but rather awfully closed-minded about things. And, of course, by "the common folk," I mean much more than the Marxian proletariat; indeed, quite easily the majority of socialized man does not recognize sounds other than that containing some elements of melody, rhythm, or harmony, and at times, even things containing some of those elements (see the oft repeated claims of "rap is not music" made by otherwise intelligent individuals).
One argument that could be made regarding music as a whole is that there are few, if any, defining features, other than sound. One account of music by musicologist Jean-Jacques Nattiez implies that, as there are no universal concepts of what music consists of, music has variable constructions, and perhaps need not be created by man.
Famous (or, depending on one's social circle, perhaps infamous) composer John Cage was in agreeance with such a notion -- he was well known for his "non-musical" music, in particular his piece 4'33", which is composed in three movements, each consisting of no more than a tacet -- in other words, Cage's piece was four minutes, thirty-three seconds long of little more than silence. Of course, there was no literal silence: when he performed the piece, Cage lifted the lid of a piano, sat at the bench, and closed the piano, and that was that. Undoubtedly, there was ambient noise in the concert hall the piece was performed in, and certainly such sounds would be heard, likely unintentionally by the creator of the sound, even during Cage's masterpiece (of sorts).
Who are we to merely pass over both natural and unnatural sounds as nonmusical? Perhaps by examining our surroundings more closely for elements of something we think we know -- music as one of the most primary examples at hand of something we claim to know so intimately -- we will not only stretch our perceptions of the thing we know as music, but enhance our very state of being. After all, where better to start than that which we think we know best?