Based on the search results, Taylor Swift's Eras Tour features surprise songs that she performs each night, and she has vowed never to repeat any of them. She has already performed a wide range of songs from her various albums, and the remaining surprise songs vary depending on the city and the album. The exact list of remaining surprise songs is not clear, but there are less than 40 songs that she has never performed from her ten albums. Fans can check the list of surprise songs she has already performed in each city to get an idea of what she might perform in the future.