The world of music has some resemblance with the natural world. Just as happens in nature with living beings, but at a much quicker pace, musical instruments, genres and styles are created, offered to the public, and then may succeed or not in conquering a place in the musical world. Success and popularity, furthermore, can be fleeting or stable, and their object, in turn, may remain more or less the same for a long time, or evolve. It is not always clear why a particular instrument or genre gains recognition, and another does not; instruments with beautiful timbres fail to survive, and others which are not substantially better become extremely widespread.