Linking Audio Tracks
Song One is able to control the playback of songs and audio tracks that you have added to the music library of your device. The music library is part of the macOS and iOS operating systems. You access and maintain it with the Apple Music app:
- The Apple Music app manages your music library. It is used to stream songs from the cloud and play audio tracks saved to your hard drive/storage space. The optional Apple Music subscription enables you to play and download content from a catalog of over 70 million songs.
This chapter provides a brief overview of the Apple Music app as it relates to Song One. If you want to learn more about the Apple Music app or your music library consult Apple online help.
To learn how to import your own audio tracks directly into Song One (without using the Apple Music app) see Importing Audio Backing Tracks.
To allow Song One to control a song in your music library you must create a link to it. Links are added in Song One's 'Song Info' window:
Tap/Click on the icon in the upper right corner of the side panel and select 'Song Info' from the pop-up menu. (If the side panel is not visible tap/click on the vertical mark at the left side of the screen.)

Go to the 'Backing Track' label and tap/click on the audio wave icon to the right.

Select 'Link Music Track' from the pop-up menu.
A window will open with the content of your music library.
Choose the 'Songs' section and select a backing track by tapping/clicking on the desired song or audio track. (If the 'Songs' section is empty see 'Downloading Songs' and 'Adding Audio Tracks' below.)
The selected backing track will be linked to the current song in Song One as indicated by the chain link icon:

This will enable the automatic playback of the audio file in Song One when the lyrics are auto-scrolled. (See play mode to learn more.)
Songs that are streamed from the cloud have to be downloaded to your device before they can be linked to Song One.
Tap/Click on the red cloud icon in the Apple Music app to download a song to your music library. Alternatively you can select 'automatic downloads' in the settings/preferences of the Apple Music app.

Add your own audio tracks to your music library by dragging them into the Apple Music app.

The Apple Music app allows you to add metadata to the songs in your music library. Basic metadata such as artist and title are automatically transferred to Song One when you create a link to the song.
When you sync your music library via iCloud the metadata are used by Song One to locate the linked backing tracks on each device. The following metadata values are examined:
- title
- artist
- album
- album artist
Add at least a title and an artist to ensure the correct audio file is identified.
Add metadata to your own audio tracks by selecting them individually in the Apple Music app and choosing 'Info' in the 'Song' menu.

Enter the metadata values before linking an audio track to Song One. Changing them afterwards will break the link.

A broken chain link icon is shown in Song One's 'Song Info' panel when a linked backing track cannot be located:

To fix a broken link launch the Apple Music app to verify if:
... the originally linked audio track has been removed from the music library of the device: add the audio track again.
... a red cloud icon is shown next to the audio track indicating the song has not been downloaded to the device: download the audio track to the device.
... you have not signed in with your Apple ID, enabled iCloud or authorized the computer device to access the songs of your music library: see 'iCloud Syncing' at the bottom of this chapter.
Alernatively you may either ...
- tap/click on a broken link icon/label to remove the link from Song One on all iCloud-synced devices.
- or tap/click on the audio wave icon to the right to add a new link as explained at the top of this chapter.
Tap/Click on the chain link icon to mute a backing track when the lyrics are auto-scrolled. The icon will change into an open chain link icon. (Tap/Click on the open chain link icon to unmute the linked backing track.)

Linked backing tracks are playable on all your iCloud-synced computer devices with a one-time setup. Your music library and Song One's backing track links are synced, provided:
... you are signed in with the same Apple ID on each device and Song One is enabled to use iCloud.
Go to
- macOS: System Preferences -> Apple ID -> iCloud (Documents)
- iOS: (System) Settings -> Apple ID -> iCloud (Apps using iCloud)

... you have authorized/enabled each device to access the media content of your music library.
Go to
- macOS: (Apple Music app) Account -> Authorizations
- iOS: (System) Settings -> Music (Home Sharing)

... you are signed into your Apple Music account on each device.
Go to
- macOS: (Apple Music app) Account -> Sign In
- iOS: (System) Settings -> Media & Purchases (Account Settings) -> Apple ID

... you have selected the option to automatically download and sync your songs to each device's music library in the Apple Music app.
Go to
- macOS: (Apple Music app) Preferences -> General
- iOS: (System) Settings -> Music
