Final answer:
The music theme 'Saints' is a song sung by a female pop singer, with one example being the version by Leslie Feist.
Step-by-step explanation:
The music theme 'Saints' is sung by a female pop singer. While the question does not specify the name of the singer, it is important to note that different versions of the song have been sung by various artists over the years. One example is the version by Canadian singer Leslie Feist. She released her rendition of the song titled 'The Water' in 2006, which is based on the traditional hymn 'When the Saints Go Marching In'.