How do I copy music to my iPhone using iTunes 11?

Solution 1:

If you start draging arround tracks or albums there should open at the right a bar within your iPhone/iPad/iPod. Drag the track/album on it.

Solution 2:

1. find the very top left control button
2. click on the downward point triangle next to the control button
3. click Show Menu Bar on the drop down menu
4. on the Menu Bar click on View
5. click on Show Sidebar on the drop down menu
6. now you should be able to see your device on the left side bar
7. drag your music to your device as you please.

Solution 3:

I got it by clicking on the iDevice towards the upper-right, under the Info tab scroll down and check the box to Manually manage music. It will warn you that it needs to erase the library on your iDevice, proceed knowing that it will clear your music off your iDevice but you can then copy the music from your computer's iTunes library back on to your iDevice. Worked with my iPhone 4 6.0.1 iTunes 11 Windows XP