Q: When I listen music, sometimes for specific pieces, it's skipping to another song suddenly ?

Hey androue,

Thanks for using the Apple Support Communities. I understand that you are experiencing issues with songs skipping on your iPhone 6. Did you sync these songs from a computer? Or were they purchased/imported from another source other than the iTunes Store? Check out the following resources for helpful information:

iOS: Songs or other audio content are skipped during playback - Apple Support

http://support.apple.com/en-us/HT203341

Troubleshooting songs that skip - Apple Support

http://support.apple.com/en-us/HT203351

Thanks,

Matt M.