iPhone 5 refuse music

I am extremely sure this has been covered before, but I can not find this specifically.

I have music downloaded from soulseek p2p on an EHD from my old pc. Old pc is gone now. My music on EHD will not drag and drop onto my iPhone5 on other pc's, nor will it on my iMac since its read only. My iPhone 4 had drag and drop capabilities I used, but the same thing isnt working now. Also on my iMac, the main computer, when I registered it, I checked 'Manually manage..." but reconnecting it elsewhere, it remains unchecked. Is it the music format? Does my iPhone have to have music from its main, synced computer only? I am 100% lost