overtone

I'm translating Helen Keller's "Three Days to See". Here are the sentences.
My third day of sight is drawing to an end. Perhaps there are many serious pursuits to which I should devote the few remaining hours, but I am afraid that on the evening of that last day I should run away to the theatre, to a hilariously funny play, so that I might.
How to comprehend the underlined phrase?

FH, have you consulted the dictionary?

overtone/ˈəʊvətəʊn/ ▶noun
1 a musical tone which is a part of the harmonic series above a fundamental note, and may be heard with it.
2 a subtle or subsidiary quality, implication, or connotation.
3 Physics a component of any oscillation whose frequency is an integral multiple of the fundamental frequency.

The second definition is the relevant one. Even in the process of striving by the human spirit, there is a quality of comedy that can be detected.

Thanks Natkretep!!!