How do you draw insightful comparisons between contrasting pieces?

With questions focusing on two contrasting pieces, it is sometimes difficult to find areas of similarity. If you can, this can be a useful starting point for exploring the differences. An effective approach is to annotate each score, colour coding points on each of the components of music that you can be asked on in the exam: harmony, tonality, rhythm, instrumentation, texture, melody and form. This will make it easy to compare each component across the two works, and the likelihood is that there will be some common ground.As an example, if the question was on harmony and tonality you might look for perfect cadences in both pieces. If they're there then both can be considered tonally grounded. From this starting point, you can then explore what keys the cadences are in - are they closely related or further apart? You can also look at what characteristics the perfect cadences have - are they reinforced by lots of chords I and V before and after, or are they approached and departed from more subtly? Does the composer place them where we expect them, or are they delayed, with interrupted cadences provided instead? From this, you can write an answer that recognises the fundamental similarities of the two works - that they are both tonally grounded through perfect cadences - but you can also acknowledge subtle differences. These differences can then be extended to relate to the meaning of the piece, and why composers have treated the same cadence differently.