The new iTunes 10 User Interface is creating a lot of discussion both from users and Cocoa developers. Whenever a program as familiar as iTunes is changed it always generates a big reaction (both positive and negative). My instinct is always to give it a week or two before reacting to see if the change grows on me with use. The change that certainly made me do a double take is the change to the toolbar with the close/minimise/maximise buttons rotated from a horizontal to a vertical layout. The title bar which previously just said “iTunes” has also disappeared.
As well as mimicking the layout of the buttons in the iTunes mini player this layout seems to have been done to save space in the iTunes toolbar. There is some debate as to whether this is a violation of the Apple Human Interface Guidelines (HIG). Certainly the HIG does say that all windows should have a title bar. It does not say if the close/minimise/maximise buttons should be arranged horizontally or vertically. All the examples in the HIG show the buttons arranged horizontally and that seems to be the way that most Cocoa apps do it with the possible exception of the iTunes mini player.
Anyway I will leave it to the HIG gurus to argue the pros and cons. I do suggest you give it a week but if after that it still annoys you there is a simple way to revert to the old style. Quit iTunes and then from a terminal window:
$ defaults write com.apple.iTunes full-window -boolean YES
Restart iTunes and you will be back to the familiar toolbar and title bar layout:
If you want to get back to the iTunes 10 default layout as Steve intended:
$ defaults write com.apple.iTunes full-window -boolean NO
(Tip of the hat to the cult-of-mac blog for the original tip)