Strange problem with file upload

Thank you @kirasiris, i made all of yur suggested modifications but no way. It's not working.
I want to ask one question: Is it possible that a file has mp3 extension but is not mp3 file?

This is what your code should look if you want it to send it to a database and into a folder.

PHP Code:

// Upload mp3/Ogg File
 $config['upload_path'] = 'uploads/musiques/';
 $config['allowed_types'] = 'mp3|ogg';
 $config['encrypt_name'] = TRUE;
 $config['file_ext_tolower'] = 'TRUE';
 $config['remove_spaces'] = 'TRUE';
 $this->load->library('upload', $config);
 $this->upload->initialize($config);
 
 
 $file_name = 'mymusic';
 
 if(!$this->upload->do_upload($file_name)){
 var_dump($this->upload->display_errors());
 $file_name = 'uploads/musiques/nofileselected.jpg';
 } else {
 $post_image =  $this->upload->data('file_name');
 }
 
 // If you want to send it to your database as well, you have to put it like this:
            $data = array(
 'slug' => $slug,
 'title' => $this->input->post('title'),
 'mymusic' => $post_image,
            ); 


try and see if it works, and to respond your second question about uploading a file that looks like an mp3 file but its not, I will highly recommend you to convert any file into mp3 before uploading just to  make sure you dont mess with uploading class; or if you have any idea of what the real extension of the file is, then added it to the allowed_types parameter and see if it works.

My code exactly look like yours except the part of sending into a database but it still not working.

Just to be sure that you understand my problem, I have to remind you that the upload works, but it does not work for all mp3 files. Some mp3 files are correctly uploaded others not. Why? I have no idea. May be it's about the file i'm trying to upload.

Simplicity is the ultimate sophistication