Here is a link to another forum that offers this solution for the delete.
matt.choules
Member with 372 posts. Join Date: Sep 2003
Location: Nottingham
Experience: Intermediate
14-Jan-2012, 06:55 AM #3
I found I could delete my music from iPhone, but only by doing this:
Settings > General > Usage > Music
Then swipe Delete.
I found this finally deleted all my music from my iPhone, then I started again by syncing my music from iTunes.
Hope this helps,truenorth