If you were to ask graduates of any music conservatory, “What is the best-known example of an art song for voice and piano in classical music?” chances are that nine in ten would say, “Franz Schubert’s Erlkönig (Elf King). Schubert began his now-famous song after reading a poem by the German poet Johann von Goethe. The video here provides the poem spoken in German with English subtitles as well as cartoons to depict the story—but no music.
https://youtu.be/r1Mzoq3n_PM
As you watch the video, imagine that your job is to set the text and cartoon to music. What would you do? What mode would you choose: major or minor? How would you represent the sound of the galloping horse? Which voice part would you put in a higher register: the son or the father? What mode would you choose for the flowers on the beach and the mother dressed in gold? And, when the horse slows down and arrives at the inn, what would you do to the tempo? These are the kinds of decisions that a composer like Schubert would have had to make before setting pen to music paper. Describe how you, the composer, would proceed.