Sorry, since I do not have direct access to the video or audio files, I am unable to determine the background music during Kevin Spacey's appearance at 18:53 of the linked video The Ellen DeGeneres Show.
If you are interested in this song, we recommend that you search for relevant information on the Internet, such as by searching the video title, keywords, or a music identification application to find the name of the song. Once you know the name of a song, you can more easily find its lyrics, sheet music, and where to download or purchase it.