If you have songs in the Music app that are missing information then the app may not group them by artist or album correctly. You can correct this information easily in the app. You can also modify songs so they appear on the proper albums and sorted in the right order. You can add album artwork too, and set the order of tracks in an album. This works the same way before Catalina in the iTunes app and will even work for songs obtained from Apple Music and sync with your other devices.
You can now log on to your Apple Music account in a web browser, access your music library and playlists and play your music. This gives you another way to access Apple Music and is handy if you are using a non-Apple computer or have to be logged in to a work or school Apple ID.
A new feature of Amazon Echo devices is that they now support Apple Music. Previously, you could use a number of music streaming services with Echo devices, but Apple Music was left out. With Echo dots being so inexpensive, this allows Apple Music users to hear their music in many places without needing a Bluetooth speaker or Apple HomePod. You can now ask Alexa to play your Apple Music songs, albums, and playlists. You can even make Apple Music your default service.
Apple Music and Spotify Shared Playlists are great ways to access selections of music from movies, books or represent a genre. You can find more complete movie soundtracks in Shared Playlists and also collections and "mixtapes" mentioned in movies and books.
Apple Music users can easily download playlists, albums, artists and songs for offline listening. After a while, you may have a large collection of downloaded music taking up space on your iPhone. You can easily remove these downloads in the Music app, or in the Settings app.
With the latest versions of iTunes and iOS you can set up a social profile and share playlists and music your are currently listening to with your friends. You can also follow artists and special Apple Music channels to see the latest news and media from your favorite artists.
A new feature for Apple Music subscribers is the ability to view lyrics for most songs. You can view them in iTunes in Sierra while the song is playing, or in the Music app in iOS 10.