Just bought a iPhone 4s and began to upload music on to it today, did a couple of albums, filled out all the get info stuff, uploading the album artwork etc, but on my iPhone all it shows is the songs, the artist and album of every song is listed as 'unknown', if I go on the artist page it says I have no music, same with albums, yet on iTunes all the artist names etc are there as they should be, how can I fix this issue cos it's really getting on my nerves!