What does the word “bow” mean in this specific context?

Question

I read a sentence in a book, The Word Power Made Easy, which was

You are boastful to the point of being obnoxious - you have only one string to your conversational bow, namely, yourself; and on it you play a number of monotonous variations.

According to most of the sources online relating to the the idiom, the word bow means the archer's bow in this idiom but then why has the author of the sentence used "playing a number of monotonous variations" after the idiom (you don't play something through a bow). I am wondering if there is any sense of the word "bow" that relates to an instrument because it is through an instrument's string that something is played.

Answer 1

You have either a bad version of that book, or you have [or someone has] copied it badly, or you have misread it. The thing that has 'one string' is a (figurative) violin.

You are boastful to the point of being obnoxious—you have only one string to your conversational violin, namely, yourself; and on it you play a number of monotonous variations: what you think, what you have done, how good you are, how you would solve the problems of the world, etc. ad nauseam.

Word Power Made Easy by Norman Lewis (Google Books)

Answer 2

To "have more than one string to your bow" means, in this context, to have more than one skill or style. This indeed comes from archer's bow, which has a string that is pulled to shoot arrows. The idea is to have a spare component in case the main one fails.

Using this idiom with the variation "have only one string to your conversational violin" is a play on words, since a violin is a musical instrument that has strings, and is played with a bow. Here both "string" and "bow" have different meanings but the idea is similar - having only one string is being limited in what you can play or express.

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