Just as an experiment, I thought I'd add an audio (MP3) file to my ebook, to see if it would work, following Liz Castro's tutorial on how to do it (I even sprung a whopping $5 on her book about adding audio/video). Apparently audio and video only currently work in iPads and Nooks, but I can certainly attest that they do indeed work no problem in the former (I don't have a Nook, but I'll take her word for it).
The only problem is that adding in the <audio> tag gives my perfectly-valid ebook an error (or series of errors) related to that tag.
Okay, so now my book doesn't validate -- but just how disastrous is that, considering it's merely because of that audio file? For devices that don't support it, they get a "Sorry, your device doesn't support embedded audio" message instead, so what's the big deal?
Is it utterly sacriligious (so to speak) to have an ebook with just that error, related to the included audio file? Or is this so heinous that I should just scrap it and not put it in at all?