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Syncing The Music Folder Between Two Macs


This guide explains the procedure for creating a ChronoSync Express Synchronizer document to keep each of the following Home sub-folder in sync between two Macs.

  • Music

There is a structured set of steps that must be followed to use ChronoSync Express for the Music folder which contains the iTunes Library. This guide covers the steps necessary to successfully sync the Music folder between two macs. ChronoSync Express can not merge two different iTunes libraries into one but it can keep them in sync once they are the same.

This guide is linked as part of the "Sync The Home Folder Between Macs Using ChronoSync Express" Guide but can be used stand-alone to setup a synchronizer document to keep either or both of the above folders in sync between two Macs.

If you are syncing 'Desktop', 'Documents', 'Public', or 'Downloads', then follow this Guide instead: "Syncing The Desktop, Documents, Public, or Downloads folders between two Macs."


As a reminder from the Sync Home Folder guide, there are some cautions you should take before embarking on keeping one or more of your Home sub-folders in sync:


Before running any sync for the first time, make sure to backup all data on each Mac in the event something goes wrong. Since home-to-home files syncs are usually bi-directional syncs (syncing files both directions), this is especially important. When running any sync, ChronoSync Express can archive any changed or deleted files, but it is a lot easier to restore files from a backup rather than restoring from the ChronoSync Express archive. ChronoSync Express, Time Machine, or any other backup application can be used to perform the backup of each Mac.


Home folder syncs must only be done between identical versions of macOS. For example, do not attempt to sync between Mountain Lion and Mavericks, and avoid syncing between different versions of the same OS (10.10.1 vs 10.10.2).

Also for Home folder syncs, ensure all apps such as iPhoto, iTunes and iCal are the same version. Of course personal files, including documents, raw media files, downloads, etc., can be synchronized or backed up to any OS version or any device accessible via Finder using the Mac ChronoSync Express is installed on.


Never attempt to sync files outside of the home folder such as 'Applications', 'System', or 'Library' between two Macs. Problems can arise if Applications, or System files are synced that can easily result in application failure or a corrupt OS. In syncing two Macs, the focus needs to be on the home folder and the data files stored therein.


Make sure you have the same version of iTunes on both Macs in order to synchronize the Music folder which contains your iTunes Library. However, music files, like .mp3 files, can be synced between any OS that your Mac can copy to, including Windows.


The Music folder is where music and audio files are generally stored. It is also the location of the iTunes Library. The iTunes Library is a folder that stores all the music files in a complex way. ChronoSync Express can not merge two different iTunes libraries into one but it can keep them in sync once they are the same. The iTunes Library can be synced back and forth between two Macs as long as a few rules are followed: always run the sync when switching Macs and always run the sync from the same Synchronizer document.

Also, this guide assumes you already have ChronoSync Express installed on your primary Mac, and ChronoAgent installed on the Mac you will be syncing these folders to. If you don't already have this setup, just review the 'Setup Steps' in the "Sync The Home Folder Between Macs Using ChronoSync Express" Guide.

Many of the steps performed can be accomplished by using a standard file sharing connection and you technically don't need to install ChronoAgent. However, ChronoAgent offers better performance, security and reliability versus a standard file connection. It also eliminates common problems, such as permission errors, that typically occur when using standard file sharing.


Create Master iTunes Library

ChronoSync Express cannot merge two dissimilar iTunes libraries. The first step in syncing the Music folder is to create a master iTunes library on one of the Macs. This guide assumes that you use the ChronoSync Express Mac to create the master iTunes Library. There are other applications that will merge iTunes Libraries, just search the Mac App Store. Also, you can read Joe Kissell's article on how to Merge two iTunes Libraries.

Of course, this all assumes that you don't already use iCloud/iTunes to keep your iTunes Libraries in sync. If that is the case, you don't need to go any further and instead allow iCloud/iTunes to handle keeping the libraries in sync. It is suggested that if you do use iCloud for synchronizing this type of media, you should simply exclude your iTunes library from any home-to-home syncs that you may be performing, using the Analyze panel's Exclude function.

Backup Non-ChronoSync Express Mac Music Folder

On the Mac that doesn't have the master iTunes Library, make a backup of the Music folder before running any syncs. You could simply drag the Music folder to your desktop, or use ChronoSync Express to create a backup of that folder on an external drive or NAS.

Empty Music Folder on Non-ChronoSync Express Mac

Open the Music Folder on the Mac that does not have the master iTunes Library and drag the contents to the Trash. You need to start with an empty Music folder so that the first sync will result in everything from the Master Library on the ChronoSync Express Mac replacing all Music files and folders on the non-ChronoSync Express Mac. Be careful not to delete the parent Music folder located in your Home folder.


Step 1. Create a New Synchronizer Document

Launch ChronoSync Express. Upon launch, the Document Organizer window is displayed. Choose 'Create a new synchronizer document' to create a new sync document. If the Document Organizer window isn't visible, choose 'File - > New -> Synchronizer' from the menubar or use the shortcut keys COMMAND-N. Give the sync document a meaningful name such as 'Sync Desktop Folder Between iMac and MBP' if this is going to be used to sync your desktop folder between the Macs.

One of the greatest advantages of ChronoSync Express is the usage of documents. Just like a word processing document, a ChronoSync Express document can be saved as a double-clickable document. Once you set up a synchronization, all the information that you specified in the document is saved - even synchronizer options! Furthermore, this document keeps track of changes between every sync which allows ChronoSync Express to know what has changed since the last synchronization.

Sync Bidirectionally

Step 2. Choose the Operation

Choose 'Synchronize Bidirectional' from the Operation popup menu. A bi-directional synchronization is performed by selecting the most 'up- to-date' file between the two targets and making sure that file is synchronized to the other target.

Step 3. Enable Admin Access

Choose 'Local Volumes(Admin Access)' from the 'Connect to:' popup menu in the Left Target Pane. Since our example utilizes a connection to ChronoAgent running on another Mac, Admin Access grants ChronoSync Express the authority to update file ownership and group membership settings to match the user account on each of the two Macs.

Admin access allows you to access file ownership

Step 4. Choose the Left and Right Targets

Understanding the concept of targets is important to simplify the synchronization set up. We often refer to the targets as the source and destination, or left and right. Generally, the source target or 'Left Target' is the Mac that ChronoSync Express is installed on. The destination target or 'Right Target' is the Mac running ChronoAgent that you connect to. It can be helpful to have a meaningful name instead of 'Left' and 'Right' Target. To use more meaningful names, just click on the 'Left Target' and 'Right Target' labels and specify a custom name such as 'iMac' and 'MacBook Pro' to make things more understandable.

On the Setup panel, choose the targets. This is done by clicking the respective "Choose..." button for each of the targets. This will drop down a file selection sheet for you to choose the desired folder.

In this example, choose the Music folder for the Left Target by navigating to your home folder, selecting the 'Music' folder, and clicking 'Select'. You can also substitute the 'Pictures' for the chosen folder, if that is the desired folder. If you are syncing 'Desktop', 'Documents', 'Public', 'Downloads', or 'Movies', then follow this Guide instead: "Syncing The Desktop, Documents, Public, or Downloads folders between two Macs."

Choose connection profile to sync to remote mac

For the right target, click the 'Connect to:' popup menu and locate the name of the ChronoAgent Connection Profile you created when performing the 'Setup Steps' in the "Sync The Home Folder Between Macs Using ChronoSync Express" Guide. If you don't have your connection profile setup, then review the Setup Steps in the above guide to learn how to create the Connection Profile.

Now that you have the ChronoAgent connection set, click the 'Choose' button in the Right Target pane and navigate through the folders on the remote Mac to locate the 'Music' folder you want to sync to on that remote Mac. (Of course, you can also substitute the 'Pictures' for the chosen folder, if that is the desired folder.)

Setup panel with target selected

Step 5. Enable Synchronize Deletions

In most cases, you will want deleted files from one target to also be deleted from the opposite target. To do this, turn ON the "Synchronize deletions" checkbox. When this option is turned ON, ChronoSync Express will delete files in the opposite target whenever it detects a deletion, keeping the two targets identical. Please note that no files will be deleted during the first synchronization because ChronoSync Express does not yet have a past history of any deleted files.

Step 6. Enable Archiving

Enable Archiving

Enable "Archive replaced files" as a safeguard so all deleted items will be moved to an '_Archived Items' folder. This is useful in case a mistake is made and you want to retrieve a file that was replaced or deleted. Manage the size and growth of the '_Archived Items' folder by visiting the 'Archive Handling' section in the Options panel.

Step 7. Customize the Options Panel

Visit the Options panel and customize any settings to tailor the sync for your specific needs. Refer to ChronoSync Express Help for details on the options listed within this panel.

Step 8. Exclude Files or Folders

NOTE: The image below is only for example. It does not indicate which files or folders should be excluded

Customize Options

Sometimes there are certain types of files you do NOT want synchronized. An example would be if you did not want to sync some personal documents to the other computer. To do this, select the particular folder or file in the Analyze view, right-click (or CONTROL-click) the selection, and choose "Exclude". You can also choose "Exclude" from the Actions menu. An exclusion is denoted by an "X" in the status column and means that the file will not be considered during the synchronization process. When you exclude a file it will be ignored during the sync and when you select a folder, all of its contents will be ignored.


If you are following the "Sync The Home Folder Between Macs Using ChronoSync Express" Guide, then repeat the above Steps 1 through 8 to create a separate synchronizer document for each of the Music and Pictures folders you wish to keep in sync between the two Macs, then return to Step 4 in the above-linked home folder sync document.

If you are using this Guide stand-alone to setup a synchronizer document to keep either of these two folders in sync between two Macs, then continue here with Step 9.

Step 9. Run the synchronization

Once you have all the above-mentioned settings in place, perform the synchronization. This can be done by choosing the "Synchronize" icon in the toolbar of the Synchronizer document.

It is recommended that you run a Trial Sync the very first time you perform the synchronization. That way, you can peruse the Trial Sync results to make sure you haven't made a simple configuration mistake such as selecting an incorrect target. If it looks like a lot more files than you expect will synchronize, or a sync in a direction you didn't expect, you should take a step back and double-check your configuration.

Watch for the following types of issues:


Make sure to always synchronize each time you switch working to the other Mac. If you fail to do this, conflicts may arise. A conflict is when the same file has changed on both computers. Since you have to choose between one file or the other, you would lose the changes made to one of the files. If a conflict does arise, then choose the file from the computer you last used.


Since you need to synchronize every time you switch Macs, it is not practical to schedule your Home to Home Container document. Instead, you should manually run the sync every time you switch Macs to ensure the two Macs always stay in sync. Doing this will take some getting used to, but it's a habit that should be practiced.

Errors or Problems

If you encounter any errors or have any problems you can contact us by using our support form.

3 Things to Remember

Since this is a bi-directional sync designed to keep files and folders in sync between two Macs, you should pay attention to your workflow.

  1. Make sure to always synchronize each time you switch working to the other computer.
  2. Always run every sync from the source Mac using the same Container document.
  3. If a conflict should arise, choose the file from the computer you last used.

Working on two Macs simultaneously can result in unusually high numbers of Conflict errors being reported and there may be difficulty merging the changes that can occur to the same files on both Macs. Instead, consider this workflow:

To switch from Left to Right Mac:

  • Using Left Mac.
  • Run Sync from Left Mac (The ChronoSync Express Mac).
  • Choose "Left Files" for any conflicts.
  • Begin using Right Mac.

To switch from Right to Left Mac:

  • Using Right Mac.
  • Run Sync from Left Mac (The ChronoSync Express Mac).
  • Choose "Right Files" for any conflicts.
  • Begin using Left Mac.

If you have any problems while using our products or have any questions about this guide, contact us by using our support form.