I've downloaded music from a website. It is showing in Files application, but it's not showing in the music app. Any way to get it in the music app???
You need to transfer that downloaded music to "Music" folder from "Download" folder by connecting your phone with PC.
After that, restart your phone(if needed).
First of all you should have mentioned the Operation System of your phone. However, Windows 8, 8.1 or 10 Mobile will only pick files from intended folders like: for music files it's any music player app will tend to search for music in music folder which may be on phone memory or on SD Card. Same process will be applicable to other types of files. You should move the downloaded music files to music folder (In phone or on SD Card) using inbuilt files app or using PC. After this open music player app & wait for few seconds so that it can sync copied music with music player app.
Make sure that the downloaded music is in the Music library. It can either be SDCard->Music or Phone->Music.
If not, you can easily move the music file using the built-in Files app.