The type of evidence that Schlosser uses in this excerpt is anecdotal. By definition, anecdotal evidence is based on stories that may or may not be true but due to lack of hard facts. They are usually based on personal stories. In this case, there is no proof that things mentioned in the excerpt happened the way that they were described.
Answer: Ternary Form
Explanation: Ternary Form is a musical form that introduces an idea, (A) then introduces a contrasting idea, (B) then returns back to the original musical idea, often copying the first phrase how it was, maybe including some slight variation in the harmony or rhythm. A good example of a simple piece written in Ternary Form is Mozart's Andante in E-Flat Major.