An Apple iPhone 3GS and an Apple Macbook Pro are shown at the Apple retail store in San Francisco, California July 21, 2009. [Agencies]

NEW YORK– Welcome to an orchestra of the 21st century. iPhones are being used as musical instruments in a new course at an American university.

Students at the University of Michigan are learning to design, build and play instruments on their Apple Inc. smartphones, with a public performance planned for December 9.

The university said it believed the course, called Building a Mobile Phone Ensemble, is a world first. It is taught by Georg Essl, a computer scientist and musician who has worked on developing mobile phones and musical instruments.

Essl and his colleagues began using the microphone as a wind sensor a few years ago, which enabled iPhone apps such as the Ocarina that essentially turns the phone into an ancient flute-like wind instrument.

"The mobile phone is a very nice platform for exploring new forms of musical performance," Essl said in a statement.

"We're not tethered to the physics of traditional instruments. We can do interesting, weird, unusual things. This kind of technology is in its infancy, but it's a hot and growing area to use iPhones for artistic expression."

Essl said that to build an instrument on an iPhone, students program the device to play back information it receives from one of its multitude of sensors as sound.

"The touch-screen, microphone, GPS, compass, wireless sensor and accelerometer can all be transformed so that when you run your finger across the display, blow air into the mic, tilt or shake the phone, for example, different sounds emanate," he said.