From Language Log:
Christine begins her song with these lines:Let me have your heart and I will give you loveThe denotation of my soul is the aboveSo just as λx[x+1] is a function that we can define as “give me a number and I’ll return that number incremented by one”, so λ♥[love] is a function that we can define as “give me your heart and I’ll give you love”.
I love this!! More explanations of the song, the words it uses, and more at the link above. :)