So I seem to still have song with were purchased back when iTunes music was 128kbps. Now all songs in the iTunes Store are 256kbps but I can't find how to upgrade my remaining songs. If I right click on a song bought from the store which is still 128kbps it takes me to the page where there is now a "play" button beside the song. I can't find an option on the store to upgrade. I know there used to be a feature to upgrade songs to "iTunes Plus" but that is no longer available. Can anyone help?