Missing music
I purchased 2 songs recently at I tunes they where on my phone for. Couple of days than they where gone! Not sure why or where!
iPhone 6
Question marked as
If you've deleted them see if they show for redownloading : Redownload apps, music, movies, TV shows, and books from the App Store, iTunes Store, and Apple Books - Apple Support
If they don't, and if they are still in the store, check to see if you've hidden them : Hide and unhide music, movies, TV shows, audiobooks, and books - Apple Support