Final answer:
Mozart said, 'I write music with the pen, but it flows from my heart,' which reflects his belief that music was a form of artistic expression.
Step-by-step explanation:
Mozart once said, 'I write music with the pen, but it flows from my heart.' This quote reflects his belief that he had the ability to compose music that was not solely a result of technical skill, but also conveyed genuine emotion and expression. He viewed music as a form of artistic expression that came from within himself.