In the same way that "chick lit" and "chick flick" refer to books and movies enjoyed primarily by women, a "chick ditty" is a song that tugs at female heartstrings.
e.g. "Love Story" by Taylor Swift . . . a sweet tune about a modern day Romeo-Juliet entanglement which culminates in a marriage proposal. The song refers to dancing at a ball, love at first sight, stolen kisses, a prince-charming-like Romeo who overcomes every obstacle to marry Juliet, a wedding ring and wedding dress, and a happily ever after. (If you're a girl, wipe away your tears.)
I love that chick ditty!