If you were a visual artist, would you be a painter, or a photographer?
As a painter, you could create any image, representative or fantastic, impressionistic or expressive, realistic or abstract. You could create any color, use any type of medium, adopt any perspective. You would have complete freedom to create any scene, but you would also bear the burden of having to create that scene from a blank canvas. In addition to artistic intent, you must bring a fair amount of technical craft and expertise in the chosen medium, as well as an understanding of its basic principles, such as composition and color theory.
As a photographer, you capture visual images as they appear. You would be freed of the painter's burden to create the scene out of nothing. The danger, however, is that your photographs may offer nothing more than documentation of ordinary scenes. To keep your images from being merely prosaic, you must use a high degree of skill to control technical factors (such as composition, focus, lighting, exposure, and depth-of-field) that focus the viewer's attention on the details that convey the artistic meaning of the photograph.
The music composer has a similar choice between tools. The composer can "paint" realistic or abstract sonic landscapes using synthesizers that create new textures from scratch. Synthesizers can certainly mimic traditional instruments, but their real strength has always been in creating artificial textures that widen the pallette of sounds the composer may use. The composer can also "capture" sounds as they occur in life using sampling technology. And like the photographic image, a high degree of skill is required to take the sampled sounds beyond the everyday and raise them to an artistic level. Which of these tools would you use?