By Zoe Kleinman
Technology reporter, BBC News
A group of US students has created an entire orchestra out of separate iPhone applications.
As part of their studies, the group from the University of Michigan built the applications themselves and composed music for them.
While some of the applications sound similar to traditional instruments, others make unique noises.
The iPhone handsets are attached to speakers which the performers wear around their wrists.
A live concert of the students' original compositions is planned for 9 December. It will mark the end of their three-month course, run by Austrian computer scientist and musician Georg Essl.
He told BBC News that while the concept of using computers to make music was not new, the rise of smartphones had made the idea more practical.
"I come from this community of people who work on sophisticated ways of making sounds," he said, "but they tend to be very handcrafted prototypes. I realised that few people end up using them."
"Now everybody has a smartphone, the question of how you get an instrument into people's hands has disappeared."
Starting from scratch
Unlike traditional instruments, iPhones do not have to be physically modified for sound, Mr Essl said.
The in-built microphone can be transformed into a non-speech sensor, enabling students to blow into it in order to mimic a wind instrument.
The motion sensors can also be used musically - an application can be programmed to sound different when the device is tilted, for example - but the desired effect is down to the individual designer.
"In many ways, composition for us means composing the instrument as well as the music," said Mr Essl. "We can choose what a tilt will mean."
He admitted that the new technology was a work in progress that would advance as the devices themselves became more sophisticated.
"It's about playing with what you're given," he said. "The piccolo is never going to play the bass line."
Back to basics
Some traditional orchestras agree that smartphones have a part to play in making professional music.
"There are lots of applications that are incredibly useful to musicians - our piano tuner uses the iPhone tuner application to tune Steinway pianos for our performances at City Hall," said Stephen Duffy, spokesperson for the BBC Scottish Symphony Orchestra.
"Every musician I know who has an iPhone uses that application."
However, he added that most classical musicians did not take the instrument applications particularly seriously.
"Let's face it, you're not going to play a concerto on an iPhone. It would be interesting to see what people do as a group - but applications will never replace the real thing."