Usage and Grammar

Q. Is the following correct? “In one of my more popular poems . . .” Is there a hard-and-fast rule regarding most versus more?

A. Absolutely. In contexts like these, more is an unspecified but nonetheless greater quantity than less, as well as a possibly exact but unexpressed quantity less than most.  Of course, if you have a more popular poem, you probably also have a less popular one, so perhaps it’s best not to say.