Question

What idea is conveyed through this comparison of humans to lyres

Answer 1

Like a lyre with strings that always make new sounds, humans respond uniquely to different experiences.

In the stanza it says that the strings of the lyres "Give various response to each varying blast". The use of the words various and varying show that the strings are always making a different sound. This idea tha things are always different is carried into the next two lines when it states that "no second motion brings/One mood or modulation like the last." This states that the sounds are not the same from one stroke to the next.  This furthers the idea that things are different. This relates back to humans in saying that humans are all different and respond differently.