In iOS 5, the iPad's iPod app got both a name change to "Music" and a complete rethinking of the user interface. While some people may have found the new, visually-driven interface an improvement, I found it so cumbersome that it forced me to completely re-evaluate the media distribution across my devices. I wound up putting most of my music on my iPhone and only keeping the most essential of tracks on my iPad, because the navigation UI just isn't suited to a huge library like mine.
Thankfully, the changes made in iOS 6 are nowhere near as radical as those in iOS 5. In fact, on the iPad the only change I can find is a most welcome one. The design in iOS 5 had a confusing and inconsistent color scheme for shuffle, repeat and AirPlay controls, which made it all but impossible to tell at a glance what the control's state was. Apple's made a simple but important change for iOS 6: on the "Now Playing" screen, controls are now bright orange when active and light grey when inactive. This is a big improvement over the "white when active, slightly less white when inactive" color scheme from iOS 5.
Unfortunately, the Music app is still pretty much a mess on the iPad as far as navigating through the library goes. It's even more unfortunate that the forthcoming major redesign of iTunes appears to be heading in that direction on the Mac side of things. It continues to baffle me that Apple abandoned the perfectly good iPod app UI from iOS 4 in favor of this absolute mess; every time I use the Remote app on my iPad I'm struck by how much easier it is to navigate another machine's music library than the library stored on the device in my hands.
On the iPhone/iPod touch side of things, for the first time the Music app has received a significant visual overhaul. That may sound ominous considering how I've excoriated the iPad version of the app, but the changes to the iPhone version are much more modest and essentially amount to a reskinning of the interface. Navigation screens are much more monochromatic -- someone in Apple's music division must really love grey -- and active tabs on the bottom "depress" instead of glowing blue as they did before.
The "Now Playing" screen received some visual tweaks as well. Instead of just floating white controls against a black background, the back, play/pause and forward controls now rest within actual button designs. Just like on the iPad, active controls for repeat, shuffle and AirPlay now glow orange instead of blue like before. The color blue has also vanished from the volume and progress sliders, replaced with the increasingly ubiquitous grey.
Both sliders got a very subtle and admittedly nifty addition. Instead of shadowed white dots as before, the sliders now have metallic-looking knobs -- and the appearance of the "light" striking those knobs changes direction depending on how the device is oriented. It's a perfect example of the sort of attention to detail Apple puts into its interfaces; it doesn't make the app any easier or harder to use, but it does make it feel cooler.
Overall, iOS 6's re-skinning of the Music app's interface on the iPhone/iPod touch is a much more successful endeavor than iOS 5's badly fumbled redesign of the same app for the iPad. Although the visual alterations took some getting used to, they don't interfere in any way with the actual usability of the app. Considering the trend in music app design from Apple over the past couple years, that's high praise.