I have itunes match and i see all my must but half the time it doesn't play, what am i doing wrong, it's very frustrating

Question

i pay for itunes match, downloaded all my cd's and i see it on my phone but half the songs don't play,  what am i doing wrong?   i didn't think you had to actually download them onto the phone, this was the idea of not using the storage, right?

Answer 1

All iTunes Match music is downloaded to iOS devices in order to play them.  They don't stream like services like Pandora do, whch only stream the music to your device without storing it.  With iTunes Match a song must be stored on the device in order to be played.  But here's where it gets a bit confusing.
If you tap the cloud with the downward facing arrow next to a song on your phone it will download and stored on your phone and this will allow you to later delete it by swiping over the song title and tapping Delete.  In fact, you can later locate all the songs you have downloaded in this way by going to Settings>iTunes & App Store and turn off Music under Show All.  The music app will then only display the songs previously downloaded to your phone, making it easier to delete them to free up space if you no longer wish to store them on your phone.  Go back and turn Music back on under Show All in order to see your entire iTunes Match library again.
However, you can still play a song by simply tapping the title (without tapping the download icon).  When you do this, the song plays, but is still downloaded and stored on your phone as you listen to it.  The disadvantage of this is that these songs are stored in cache memory and cannot be manually deleted by swiping over the song title.  According to Apple, this cache memory is automatically cleared over time as the memory on your phone starts to fill up (by deleting the oldest and least played songs from cache memory).  If you want, you can still force this memory to be cleared by restoring your phone.
The main takeaway from all of this is that iTunes Match, while making your entire library available to play without storing the music on it ahead of time, still stores songs as you play them, or as you manually download them prior to playing them.
If your songs are not playing when you tap them while away from your wifi, make sure you have Use Cellular Data turned on in Settings>iTunes & App Store.  This allows them to be downloaded and played using your cellular data plan while away from wifi.