Just replaced my iphone 5 with another. For some reason only 60% of the mucic on my computer synced with the new phone. All songs say they are there but only 60% play. The computer says that I only purchased this 60% from itunes - whereas I purchased 95%

Just replaced my iphone 5 with another. Trying to sync content witrh icloud and my computer - did backups to both. All successful apart from my music. My computer has some 1,000 songs, nearly all bought from itunes - however, it says only some 600 were purchased (don't know why) - and the sync only seems to cover these. The phone shows the songs, album covers etc for all 1,000 and the sync said all were downloaded, but the phone will only play the 600 denoted as "purchased" on my computer. I want to have all 1,000. Can anyone advise how I get there?