It has been possible to buy the lyrics for your favourite songs since the invention of the letterpress in the 15th century when ballad sheets and engraved music were first printed. But it was not until the Victorian era that demand for illustrated music sheets reached the height of popularity.
The ability to mass produce music covers owes a lot to the invention of lithography. Lithographs were produced using wax or crayons to draw the designs on a specially prepared flat stone which was then inked.