Hi,I am sure this is as easy as falling off a log but I'm stuck on how to transfer specific tunes from iTunes on an iMac 2011 to an iPhone 6S.I have connected by USB,I have clicked on the phone in iTunes and gone to 'options' where I clicked on 'manually manage music and videos'. I clicked on 'file' and 'add to library' but after that a bit of brain fog has descended.I am hoping someone will be so kind as to give me a step by step on how to add just certain tracks to the phone?Thank you.Larry