solos
A palindrome is a word, phrase, number, or other sequence of characters that reads the same forward and backward. In the context of songs sung alone, a palindrome could be a song title or lyrics that are the same when sung in reverse. One example of a palindrome for songs sung alone could be "Able was I ere I saw Elba," which reads the same forwards and backwards.
solos
tot, solos
In the plural, it's solos.
civic
mum
solos
A palindrome for relating to a city and citizenship could be "civic." This word is a palindrome and is often associated with cities and civic duties related to citizenship.
A palindrome for the past tense of the word "do" is "did."
Civic
Bob
Bob