[AKang]

I listen to a lot of music on my 16gb iPhone 4 and I want to save some space.
Most of my music is 320 kbps MP3's although some is 256 kbps and 192 kbps. I currently have 1150 songs that take up 7.6gb of space. 

Which format do I use to save space and keep sound quality, and how can I do that? 

 

[StratocasterMan]

You may want to take a look at this thread over in the sound science forum:
 
http://www.head-fi.org/t/645023/should-i-convert-to-256-kbps-aac-on-itunes