Lovelace cited music as information that a computing machine could encode. In her notes on Charles Babbage’s Analytical Engine, she argued that the machine might manipulate symbols representing things other than numbers, including relationships among pitched sounds and musical composition.
Her example was remarkably forward-looking. Lovelace suggested that, if the rules of harmony and musical composition could be expressed formally, the Analytical Engine might compose elaborate pieces of music. This was not a claim that the unfinished machine had already produced songs; it was an explanation of what a programmable machine might do in principle.
The idea appeared in the notes she added to her 1843 translation of Luigi Menabrea’s account of Babbage’s engine. Those notes also described an algorithm for Bernoulli numbers, often called the first published computer program. Lovelace’s music example is therefore important because it shows her understanding of general-purpose computation, not merely mechanical arithmetic.