Q: I am hoping to use iTunes Match to allow me access to my 35,000 songs but not have to store them on my laptop. I have an external drive I use at home that I don’t want to carry around and prefer not to store any media on the local drive. Is this not possible as I thought it was with iTunes Match?

– David
A: iTunes Match does allow you to stream your music content from iCloud, but this is designed to work from other iTunes libraries. For example, if your iTunes library is on a desktop computer at home, you could setup your laptop for iTunes Match to access and stream content from your main iTunes library via iCloud instead of having to create and maintain two iTunes libraries and duplicate your content on the laptop.
iTunes Match relies entirely on information in your iTunes library database in terms of which tracks are available locally or online. For tracks stored locally, the iTunes database contain a path to where the corresponding file is supposed to be, and iTunes will expect to be able to find it there. When the underlying file for a track is “missing”—such as when your external hard drive is disconnected—iTunes will be unable to access the track file and unfortunately will not fall back to looking for an iTunes Match version; you simply won’t be able to play that track.
You may be able to work around this, however, by setting up a second library on your laptop and adding it to iTunes Match. You would use your primary library—which lists all of your tracks locally—when the external hard drive is connected and switch to the secondary iTunes Match version of the library when you’re travelling and don’t have the external hard drive connected.
The easiest way to set this up is to simply hold down the OPT key (Mac) or SHIFT key (Windows) when starting iTunes; you’ll be prompted to either create or choose an iTunes library.
So you would basically use the “Create” option and choose a folder to create a new empty iTunes library. You can then add that computer to iTunes Match and access your entire library from iCloud. When you want to switch back to the original library, simply repeat the process above, using the “Choose Library” option and selecting the folder for your original library.
One small thing to be aware of in this process is that while the iTunes library databases will be completely separate, your iTunes preferences are used across both libraries. Most importantly, this means that your iTunes Media folder path will be the same for both—the external hard drive when it’s connected, or a local path when not. This should not be a problem, however, unless you use the second iTunes Match library with your external hard drive connected and actually download content from iTunes Match; in this case, you will end up with duplicate files in your iTunes Media folder.
Lastly, it’s worth noting that iTunes Match is limited to 25,000 tracks. The limit applies to tracks that need to be matched or uploaded, as opposed to content you have purchased from the iTunes Store which is already available in your purchase history. Unfortunately, iTunes doesn’t provide any way to selectively include or exclude tracks from the iTunes Match service; if your library is larger than this limit, you’ll simply be prevented from signing up. So, unless 10,000 of your tracks were originally purchased from iTunes under the same account you’ll be using for iTunes Match, you’ll be forced to either find another solution or pare down your iTunes library before signing up for the service.