It appears that the Music application on your device isn't working as expected. When you try to search for a song, the application quits. I'm happy to help.
How to force an app to close on your iPhone, iPad, or iPod touch -- First, force close Music application if it's open, then -- Restart your iPhone, iPad, or iPod touch -- Restart your iPhone. Once it's returned to the Home screen, test the issue.
How to back up your iPhone, iPad, and iPod touch -- If restarting your iPhone didn't resolve the issue, please be sure to have a fresh backup to keep your personal information safe. In order to back up your Health data, the backup needs to be encrypted. iCloud does this automatically, but iTunes doesn't. If you'd like to use iTunes to back up your iPhone, refer to this article: About encrypted backups in iTunes
How to check the storage on your iPhone, iPad, and iPod touch -- A new feature in iOS 11 is the ability to delete an application, but retain it's data. If restarting your iPhone didn't resolve the issue, you can offload the Music application, then reinstall it again. Go to Settings > General > iPhone Storage, scroll to the Music application and tap "Offload App". Once the application has been removed, reinstall it again and test.
Let me know how that goes.