The new nano is rectangular rather than square and looks a bit like a mini iPhone, with a 2.5-inch multitouch display, according to Macworld's of the event, which ended with a performance by the Foo Fighters.

The new nano is 40 percent thinner than its predecessor, at 5.4 millimeters, and it has a home button to get back to the home screen more easily. And since nanos are so widely used by runners, Apple has built in a pedometer and support for Nike's Nike+ software.

It gives 30 hours of playback, according to Apple, and will go on sale in October for US$149 with 16GB of storage.

Apple also showed a new iPod touch that's thinner than its predecessor, at 6.1mm, and lighter too. Like the iPhone 5, it will have the larger, 4-inch retina display.

A new processor, the dual-core A5, will double the compute speed for some applications and improve the graphics for better gaming, according to Apple.