I try to upload mp3 and it NEVER WORKS.

i try to upload mp3 and it NEVER WORKS. WHY..???

I have tested your embedded form and I was able to upload mp3 file and submit the form. 

File that I uploaded is shown on submission page of your form. 

File that I uploaded was small and I think that you have issue when you try to upload larger files. 

File Size Limit is set to 1024 (1 MB) on your form. If you want to upload larger files you will have to increase the upload size limit or to turn it off. 

Inside of this guide you can also find how to change the file upload size limit:

Changing the File Upload Size Limit

Hope this will help. Let us know if you need further assistance.

try a 4 min song.. mp3 and it dont werk...
...

The length of the playing time of an MP3 file may mean for its file size to be larger. As mentioned by BJoanna, the file upload field has a setting of 1MB Maximum file size. A 4 minute song usually has a file size range of 3-8MB average.

But for your convenience, I have set it to 10MB max limit. Please check the size of the file you are trying to upload and likewise test the form again the file submits properly.

If you have questions, please let us know.