Sentence:  There is for example , a stunning Krakowiak that closes the first act ; the mazurka choreographed by Witold Zapala to music from Moniuszko 's opera , `` Strasny Dwor ' , may <WSD>be</WSD> the most beautiful mazurka you are likely ever to see ; there is an enchanting polonaise ; and the dances and songs from the Tatras contain a magnificent dance for the men . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)