Sentence:  One part of her audience was 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 <WSD>interest</WSD> in that which he does not fully understand . 
Meaning of the word marked with <WSD> tags:  a sense of concern with and curiosity about someone or something