When you activate iTunes Match from your computer your computer's library gets matched or uploaded to the iTunes Match server. If you activate iTunes Match on your iPod Touch, iPhone, or iPad you will see all of your matched an uploaded music appear in the music app on that device. Songs that are downloaded locally on the device will appear without a cloud symbol meaning they are physically located on the device, can be played and not use data, and if you go off the grid, they will still show up and be playable. Songs that are in iTunes Match but not on your device will have a cloud icon. You can play these songs at any time but they are being played from the server, so if you connection is bad or you go offline, you may not see them or they may not load well. In the end, the answer to you question is yes. If you activate iTunes Match, you can choose which songs or playlists are downloaded locally to a device and which ones aren't. This article may answer more questions you may have http://support.apple.com/kb/HT5637