Why do we study composers such as Bach, Mozart and Beethoven above others?

GCSE and A-Level papers (and university degrees) tend to focus on composers such as Bach, Mozart, and Beethoven because of the impact they each had on subsequent generations. Each one had a profound impact on musical culture, but that is not to say that they were the most important or well-known composer at the time; Handel was far more popular than Bach during the early eighteenth-century (not to say that Handel was not important). The way we study music means that we favour composers and pieces that had an impact on the way music was composed by others. Bach’s music is considered important to study not just because it is impressive or beautiful itself, but also because of the influence it had on future composers, such as Mozart and Beethoven.