What version of Premiere Elements are you using and on what computer operating system is it running?
For now, I will assume Premiere Elements 11, 12, or 13 on Windows 7, 8, or 8.1 64 bit.
I am not clear as to the target for your question and what you mean by
and I see it looks like adobe will only let you add the preselected audio to a video.
What is this preselected audio to which you refer?
And, what is the source of your own music? I ask this in case you are trying to use iTunes music
in your Premiere Elements projects and cannot import the iTune music files into your project.
If this is your situation, then the classical remedy is beforehand to convert your iTunes music files to
.wav file in iTunes and then import them into your Premiere Elements project with the Premiere Elements
Add Media/Files and Folders/Project Assets from where you drag the file to the one of the Timeline audio tracks.
The how to for the iTune music conversion is found in the following Apple document. If you need any help with those
details, please do not hesitate to ask, and I will clarify.
We will be watching for your follow up.