In the baroque period (and even today) operas began with the it was an instrumental introduction to the opera. eventually, these were separated from the opera and led to the creation/birth of the orchestra.

In the baroque period (and even today) operas began with the overture. It was an instrumental introduction to the opera. Eventually, these were separated from the opera in Romantic era and led to the creation/birth of the orchestra  and orchestral music such as symphonic poems, whom composers such as Beethoven and Mendelssohn began to use the term to refer to independent, self-existing instrumental, programmatic works.

can we see the cartoon?