Downloading Music

Hi there randel114,

Thanks for posting in Apple Support Communities.

To sync your iPhone 5s with your iMac running macOS Catalina, you would use Finder to do so instead of the Music app. Learn more with the steps below:

"Sync or remove content using the Finder

1. Open a Finder window and connect your device to your computer using a USB cable. Learn what to do if you don't see your device listed in Finder.
2. After your device appears in the sidebar of the Finder window, click the device to select it.
3. If prompted, trust your device. You might be asked to update to the latest version of iOS or iPadOS.
4. Select the type of content that you want to sync or remove from the horizontal list. To turn syncing on for a content type, select the checkbox next to “Sync [content] onto [user’s] iPhone.” More syncing options will now be available.
5. Select the checkbox next to each item that you want to sync.
6. Click the Apply button in the lower-right corner of the window. If syncing doesn't start automatically, click the Sync button. You may also be prompted to authorize your computer to complete the sync.

* You can only sync your device with one Apple Music or Apple TV library at a time. If you see a message that your device is synced with another Apple Music or Apple TV library, your device was previously connected to another computer. If you click "Erase and Sync" in that message, all content of the selected type on your device will be erased and replaced with content from this computer."

This information can be found in Use the Finder to sync your iPhone, iPad, or iPod with your computer.

We hope this helps.