The music-streaming service Spotify unveiled an online map called “Serendipity” on Thursday that shows when people in different cities are listening to the same song at the exact same time — or at least within a tenth of a second of each other — regardless of the city, timezone or hemisphere. The project, based on real-time data, was created by interactive artist Kyle McDonald, the company’s first media artist in residence. “There are so many ways we’re connected to each other, but sometimes we forget, or we just can’t see it,” McDonald said on Spotify’s blog.