Whistler had done a number of these nocturne paintings. The most famous of these was Nocturne: Blue and Gold Old Battersea Bridge. All of the paintings were a study of the night sky and the deep tonaity of color.  

Clearly you can see Sargent working with the same ideas, only in his scene, he has inserted a passionate Spanish dance. 
 
 
 

Note: 

• See the year in review 1879
• The Road to Madame X
• Nocturne: Blue and Gold Old Battersea Bridge.
• Two studies in White -- Whistler and Sargent