So I was looking to update my iPhone 5 to iOS8 last night and was gobsmacked to be met with the message that I need at least 4.6gb to install it 
Looking through my storage on my iPhone 5, it looks like if I delete all my music, it would free up enough space to download iOS8.
I noticed, however, that most of my music is in the cloud anyway (denoted by the cloud icon next to the tracks) but will still play if I select it.
So my question is, what difference does it make whether I have the music stored in the cloud (which still plays when selected) or actually on my phone?
If I delete it from my phone, I assume it is still available in the cloud?
Looking through my storage on my iPhone 5, it looks like if I delete all my music, it would free up enough space to download iOS8.
I noticed, however, that most of my music is in the cloud anyway (denoted by the cloud icon next to the tracks) but will still play if I select it.
So my question is, what difference does it make whether I have the music stored in the cloud (which still plays when selected) or actually on my phone?
If I delete it from my phone, I assume it is still available in the cloud?