What version of Premiere Elements and on what computer operating system is it running?
What is the source of the music which you are trying to import into a Premiere Elements project?
If iTunes, the typically solution which I give is found in the link that John as posted for you.
For your convenience
There is a problem with iTunes music and Premiere Elements (many versions).
Please convert your iTunes music to the wav version using iTunes.
If you need help with the instructions, please do not hesitate to ask.
If the iTunes conversion is applicable to your situation and you decide to convert the iTunes music to WAV version in iTunes before importing your music into Premiere Elements project, please do not hesitate to ask if you need supplemental information on the iTunes how to in the post quoted from.