Q: iTunes Match - download all songs?

Solution found.

There's been a lot of replies here and I'm not sure if this question was properly answered (and there have been a lot of other unrelated questions as well). I got this answer from another website, posted by a user named David Harthcock. I also added a bit of explanation as to why this glitch is happening. The difference is between iTunes Match and iTunes in the Cloud. iTunes in the Cloud was/is a way for your device to sync with your computer without plugging in manually. iTunes Match somewhat supersedes that by allowing you to choose when to sync, but also to stream tracks, etc.

When you first enable iTunes Match, it asks you if you would like to sync this phone with your current iTunes Library in the Cloud. When you say yes, it authorizes your phone for iTunes in the Cloud. So now you’re running both iTunes Match and iTunes in the Cloud. iTunes in the Cloud is trying to sync your computer with your iPhone, when in reality you want to use iTunes Match to choose what and when to sync. As a result, you can simply disable iTunes in the Cloud for your iPhone without disabling or affecting iTunes Match.

– Open iTunes on your computer and click on Store > Account

– Under “iTunes in the Cloud” click “Manage Devices”

– Remove your iPhone from your devices

You shouldn’t need to do anything else. Obviously if tracks are in the process of downloading on your phone, cancel them, and follow other’s instructions for pruning the leftover tracks on your iPhone. If you want to use iTunes Match on any other devices, just make sure to follow the same procedure.

Here is the more intuitive way:

1. Select iTunes > Preferences, and go to the "Stores" tab.
2. Be sure the following are checked: "Music", and "Always check for available downloads"

Just wanted to tell you that you are a genius.  That was the simplest fix ever to a problem that's been annoying me for like 2 years!  Thank youuuu!