Synchronising music files to my iPad

IMac 2,8 GHz Intel Core Duo, 4GB 800 MHz, OSX 10.8.5

iPad MD542FD/A 64GB IOS 8,3(12F69)

I allways synchronize my complete music between these 2 products

For some time now I can not synchronise the new music content from my iMac to the iPad, The files show on the iTunes screen in a opace (pale) format with some kind of a circle symbol at the beginning of the line.

I think this problem occured after one of the recent iTunes updates?! The constant change of the user surface of iTunes is annoying I would rather go back to one of the earlier versions. They were functional for me and I dont want to relearn all the functions after every update.

Thanks for any input, Bob