EDIT: @mufasa has clarified that many of my statements about “always needing to have the drive pluged in” are not true, and Engine DJ Desktop can handle you not having the drive plugged in just fine. Be sure to read his comments to get the full story.
Yeah, you can use an external drive to store media, but you cannot (officially) use a NAS or other network-drive to store media. You would want to make sure that at all times that you use Engine DJ Desktop, that you have that drive connected, otherwise it will freak out when it can’t find any of the tracks.
So, in a scenario where you’re on a laptop, moving around, this might not be such a great idea, but if you’ve got a desktop or machine in a somewhat permanent location, that you can keep the drive attached, it’s unlikely that you will run into issues.
There is also a benefit to this. Lets say you connect your USB drive, and you assign it the drive letter “M” for Music. You install Engine DJ Desktop and you import your tracks, create playlists, etc, and then two years passes and you get a new computer. Now you can connect that same drive to the new computer, map it to drive letter “M”, and copy over your Engine DJ Desktop Library to the new computer, and you’ll be able to upgrade systems somewhat seamlessly.
If you do use an external drive, be sure to map it to a specific drive letter so that it never switches and causes confusion to Engine DJ Desktop.
One thing to remember is that when you import tracks into Engine DJ Desktop, it is not copying them anywhere, it just remembers where the tracks are located relative to the machine, so you always need to have those tracks accessible when you open Engine DJ Desktop.
So, you should be able to purchase a drive, format it, assign it to a specific drive letter, copy over as many tracks as you can (and honestly I’d leave like 1GB of free space on the device, don’t fill it COMPLETELY) and then import those tracks into Engine DJ Desktop.
You can do something such as place the rest of your tracks in ~/Music/Collection/, import those tracks, and as you add more tracks to this location, import them to be added to your Engine DJ Desktop Library.
Some people would recommend that you do something to bucket your tracks, so something like ~/Music/Collection/2024, or even more granular, such as ~/Music/Collection/2024-01, ~/Music/Collection/2024-02. This will prevent any single directory from having a ton of files, as well as help you to import new tracks easily.
One thing you have to watch out for is that with Engine DJ Desktop, if you store your tracks in ~/Music/Collection/2024 and you drag and drop the 2024 directory into Engine DJ Desktop to import, it will create the 2024 playlist, and import those tracks.
But if you drag and drop the 2024 directory again, it’s really dumb, and instead of adding new tracks to your existing 2024 Playlist, it is going to create 2024-2, and import everything again. You have to go into the 2024 directory, select the specific files/tracks you want to import, and drag and drop them onto the playlist to add them. This is another reason why “bucketing” your tracks is helpful.