[AlPe]

EDIT: Please see the next message.

I keep the text of my previous message in the spoiler:

Spoiler:

Originally Posted by maestroc

I'm trying to publish a book of short sheet music pieces exported from a music notation program that provides export to epub 3 format.

This is quite cool: what is the name of the program?

Originally Posted by maestroc

First error is:
ERROR ITMS-9000: "ChristmasCarolsAltoSaxIBookv3.epub: OEBPS/content.opf(24): assertion failed:
media overlay items must be of the 'application/smil+xml' type (given type was ''). This error occurs 39 times." at Book (MZItmspBookPackage)

Actually, in the content.opf you posted, the Media Overlay resources (SMIL files) are not declared at all. In the <manifest>, you should have an <item> for each SMIL file, which you do not have. (Moreover, the media-overlay property of the <item>'s corresponding to XHTML pages is set to "a001", "a002", so these missing <item>'s referencing to SMIL files should have id's "a001", "a002", etc.). It looks like the export routine of that program is buggy.

To fix this error, you need to add to your <manifest> one line for each SMIL file, like this:

<opf:item id="a001" href="path/to/p001.smil" media-type="application/smil+xml"/>

(adjust path/to/p001.smil according to its location in your package)

Moreover, since you will probably also have some audio file for each XHTML page, you will need to declare them as well:

<opf:item id="m001" href="path/to/p001.mp3" media-type="audio/mpeg"/>

(the media-type depends on the format of the audio file)

Originally Posted by maestroc

Second error is:
ERROR ITMS-9000: "ChristmasCarolsAltoSaxIBookv3.epub: OEBPS/content.opf(21): assertion failed:
global media:duration meta element not set" at Book (MZItmspBookPackage)

You need to add in the <metadata> element the following:

<meta property="media:duration">HH:MM:SS</meta>

and substitute HH:MM:SS with the total duration of your audio.