I am working with an author to typeset their prose. It is a sizable book with a dozen of chapters in which characters sing songs and read verses from various media. The author wants a list of all poems in their book to be included somewhere. I suggested that like in science books the list should be placed in the front matter where list of figures/tables would normally reside. The author is unsure of the proper location, leaning towards the end of the book, after the index, and we are looking for advice.
This is fundamentally a matter of creative preference and desired effect. There is not a right answer for every book, although there might be a right answer for your book:
The purpose of the list, the nature of the overall text, and the length of the list are considerations that you can use to decide where to put a list of media titles.
If this is a non-fiction reference work, then either in the frontmatter or an appendix would be appropriate, depending on how you expect readers to move through the text.
If this is a work of fiction published for entertainment of the reader, usually you ought to put it in an appendix. The longer it takes for your reader to reach the “meat” of a novel, the more readers you lose. Putting it in an appendix needn't equate to burying it, though. Listing the appendix in the table of contents and titling the appendix to clearly indicate what it contains will signal to curious readers that there is interesting meta-information about the book to be had there.
Length also factors into the decision. If it's a short list—for example, of half a page—listing it early can serve to pique the curiosity of a reader of a sequential work or signal something about the style of the work, much like a dramatis personæ says certain things to a reader and makes them curious how these people are going to be relevant in the story. Conversely, if the effect of putting it before your readers early is undesirable—perhaps it makes it seem more stately and formal, when the rest of the novel is a romp, and the contrast is not itself comedically helpful—then putting it an appendix avoids it.
Regardless, the common concern is how your readers will move through the work. If you expect readers to read non-sequentially, then a long list up-front can be useful as a guide, especially if no other guide is provided. If you expect readers to move through the text sequentially though, you don't want them to wade partway through a long, dry listing of titles to find the “real beginning”, forcing them to either suffer, or to disengage and hopefully re-engage as a non-sequential reader to find the material they desire.