Electronical publishings could include multimedia, like videos or music/soundsnippets. How well does that go together with fictional writing? Could that add something to the atmosphere? Or would it distract the reader too much and should be avoided?
If it's going to make the reader stop reading, don't do it. Your goal as an author is to absorb the author into your world and make them forget about anything going on around them. If a reader has to stop reading to watch your video or listen to a sound snippet, you're not accomplishing that goal. Instead, you'll annoy your reader and they won't want to finish reading your book or read any more. Electronic publication is also still new and with a lot of glitches still. If you throw in multimedia, you're just asking for more trouble. Readers also get frustrated if things don't work properly, so insert multimedia and having it break, will lose you readers.
"Multimedia" can include illustrations, which have been used to accompany text for centuries. In that sense, using multimedia for fiction is well-established.
Using music or video to accompany a story is a very interesting idea, and personally I'd encourage you to experiment, as it could be extremely effective. At the same time, doing this sort of experiment severely limits the ways in which you can present your story, as you need online storage, and a place where people can access your story and its accompanying materials.
The question is if you are going to write a book (intended to be read as a book on some book-style device, eg. e-book reader or tablet), or a transmedia story for the internet.
In first case it would be better to limit multimedia to minimum (make them rather illustrations than content itself).
On the other hand if you are writing for readers who are in a mood for browsing internet, switching tabs etc., rather than to read your work from beginning to the end without distractions, it would be better to split the book into smaller parts (lexias) to be read on its own, which could be multimedia but do not require one attention span for both paragraph text and videos or audios. This way the model reader reads one or two lexias, leaves for distractors (Facebook, other websites, lol-cats etc.), and then returns to reads next one, and the distractions should not degrade the reading process.
I suggest two main factors to be taken in account when writing such texts:
- Read should be able to pause reading. Pausing videos is obvious. On the other hand paragraph text (with long paragraphs) does not allow user/reader to pause it. When (s)he loses focus the place where (s)he stopped reading is lost. To solve it I split my works into smaller parts (one screen) to be read at once, and instead of writing scrollable block of text I add hyperlinks or buttons (Next/Back or intertextual links depending on layout of website I designed for publishing the story). It is step toward hyperfiction but it does not stop you from making the story itself still linear.
- Distractions should not break text comprehension. Parts requiring reading them at once should be one lexia (one screen, one part, whatchamacallit), and if part bigger than several paragraphs / one screen requires to be read at once to remain comprehensible, it should be rewritten to allow distractions.
For above reasons in my (hyper)texts lexias containing multimedia do not contain more than one (or two short) paragraphs of text.