There were several upgrades from Apple last week, starting with OS X. This had a new version of iTunes that organises sections differently, giving a less cluttered interface. With the update to OS X there were also several security updates.
Just after I had updated the iPad Air 2 to iOS version 9.3.2, reports suggested this was causing some 9.7-inch iPad Pro users to have serious difficulties, so I updated that too.
The reported problem concerned an Error 56 which relates to hardware. The update may have failed to recognise fingerprint firmware correctly on some devices. By the end of the week, Apple was investigating (unsurprisingly) and pulled the update on Friday evening for the iPad Pro. None of the devices I had showed any problems. Perhaps it was my imagination, but afterwards, the sound on Apple Music Radio on the iPhone sounded enhanced: more depth.