If you didn't know, in XY there are two themes from previous games that were remastered and put into XY as pieces of music. These two were Jubilife City and the Emotion theme from BW. The emotion theme is played when talking to your rival in Coumarine City, but I am not aware of where the Jubilife City theme plays.
By talking to a woman in Snowbelle City.
“but also a wintery piano rendition of Jubilife City, aptly placed in Snowbelle City”
Source Source 2 Source 3