If you want to hear music from your portable device here is a very simple way to do this without any internet connection 

you can download musics directly from youtube.com as MP3 file into your portable device!

First of all go to youtube and search for music that you like and copy the address bar as in below picture:

then go to http://www.youtube-mp3.org/ and paste the address into the box shown in below picture:

and then click on "Video in mp3 umwandeln" button then it will give you direct link to download music as mp3 file into your device.