There's no debate Babbage was behind the Difference Engine. However, Lovelace's article on the Analytical Engine did not just expand it by demonstrating a prog

There's no debate Babbage was behind the Difference Engine. However, Lovelace's article on the Analytical Engine did not just expand it by demonstrating a programming language. It included physical differences to Babbage's - and this is because she didn't just sit and watch, she assisted on the design of the machine itself. > Again, it might act upon other things besides number, were objects found whose mutual fundamental relations could be expressed by those of the abstract science of operations, and which should be also susceptible of adaptations to the action of the operating notation and mechanism of the engine. Supposing, for instance, that the fundamental relations of pitched sounds in the science of harmony and of musical composition were susceptible of such expression and adaptations, the engine might compose elaborate and scientific pieces of music of any degree of complexity or extent.