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 <WSD>connoisseur</WSD> , 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:  an expert able to appreciate a field; especially in the fine arts