Some of my best writing, I have done while listening to music. If you take a look at one of my writing playlists on Youtube, you can find that I draw a lot of inspiration from very cinematic music. It has been said that listening to Mozart helps one to concentrate and be productive in the mental arena. Honestly, I don't think it has to be Mozart, but I think that music does help 'grease the wheels' and make it easier to be creative.
It is like surrounding yourself with artwork that inspires you, regardless of any talent you might have for the medium you are drawn to (ie. Photography, painting, etc.). The artwork or music serves as a starting point for the growth of your ideas. It is possible to argue the same about what we read. (Though there you must be careful to maintain your own perspective upon matters.)
The creative process is, in some respects, like growing a crystal. Can it occur on its own at any place with out external influence? Yes, as well as being begotten by earlier work we have done. (Think of this as crystals growing upon other crystals.) In many cases, however, our work is started by the germ of an idea. This is the 'base' from which our crystalline structures develop.
It is important to note that the 'base' for crystals will be different with respect to what type of crystal develops. Emerald is found in the same location as beryl (being a related stone). It is also found where there is calcite and pegmite. In terms of our storycraft, our crystal may be a fantasy story. It may develop from our reading fantasy, including genres of fantasy that don't exactly match our work (high fantasy influencing urban fantasy, for example). This could be described as an emerald growing upon beryl.
It could also arise from listening to music that inspires you or other 'unrelated' sources of inspiration. Our proverbial emerald growing upon calcite. And our story could arise from previous work we have written, though not in the same genre. The proverbial emerald growing upon pegmite. Lastly, our story could develop from ideas that were inspired by work we had written previously in the same genre. This would be our fictional emerald growing upon another fictional emerald.
Some people will argue that the differences in how our 'emerald' is grown makes huge differences in the work we produce. This type of arrogance is an insult to other creative minds and spits upon their work. The differences in our 'emerald' come from what we do with it. The raw stuff of stories is the fruit of inspiration and hard work. This 'raw material' is the emerald. Our creation of the story (or any other form of art, honestly) is our mining that emerald. The editing process is the cutting and polishing of the stone.
All parts of the process are labor intensive. When mining our emeralds, it is good to get help in the process. This is where sources of inspiration come into play. They are not only the matrix from which the emerald emerges but also the tools that we use to free it from said matrix. It is my opinion that the hardest part is the beginning, is finding that emerald. After that it is just a matter of persistence and refinement.
Embrace your sources of inspiration. Create your writing soundtrack and surround yourself with art that fills your mind with ideas. Disregard the opinions of people who tell you that your choices are not tasteful or otherwise criticize your mining technique. They wouldn't recognize that emerald you are looking for and shaping. Most people don't recognize the value of our work until it is finished, sadly, and have a great deal of assumptions about the labor that goes into it.
Don't let their assumptions and attitudes stop you. With patience and dogged determination, you can craft something wonderful out of just about anything you find in your path. That's the beauty of being an artist (and authors are artists too). Go out there and be your gloriously creative, brilliant self. The world needs your emeralds.