Sentence:  His life-long friend , Serge Koussevitzky , gave unreservedly of his praise and brilliant performances in Boston , <WSD>New</WSD> York , and Washington , D. C. , to which he added broadcastings and recordings for the whole nation . 
Meaning of the word marked with <WSD> tags:  the largest city in New York State and in the United States; located in southeastern New York at the mouth of the Hudson river; a major financial and cultural center