How can I make all of the songs in my iTunes library accessible through Spotify on my iPhone

[dangreenfield2]

I just recently upgraded to premium with the hopes of being able to sync my entire itunes library to it, and have those songs be accessible on my phone. I went in and selected itunes under local files and have messed around with them a bit including adding a new file of my music folder on my deskdop (Mac) and trying to make a new playlist on itunes of all of my songs and then import that, but came up short in my efforts. Does anyone know of a way to do this? 

Another thing to note is that 99% of the songs in my itunes library are from other sources, such as conversions or downloads from Audiocastle. The thing is, some of these songs have had their spotify equivilants take their place in my spotify library, but others have not, i'm unsure why (anyone know?)

Any help would be great for a new user!