Sentence:  One part of her audience <WSD>was</WSD> totally engaged , the connoisseur witnessing a peculiarly fine performance of some ancient classic , the other part , the guest of the connoisseur , attentive as one who must take an intelligent interest in that which he does not fully understand . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)