Some songs won't delete

I'm a "Match" user so have lots of songs on my iphone (os7) through the iCloud. But I'm having trouble deleting some of the music files that are downloaded on the phone. I toggle in "settings" under "music" to have only songs show that are downloaded with the intention of deleting downloaded songs I no longer want on the phone. But on many of my downloaded songs I'm unable to slide the song listing to activate the red "delete" button. Is it related to syncing issues and how the songs got there? Bottom line, I can't figure out how to delete many of the songs off the phone....