Air guitarists’ rock dreams come true

Air guitarists’ rock dreams come true




* 18:02 28 November 2005
* NewScientist.com news service
* Will Knight

Computer vision software recognises a player’s hands and adds riffs and fret board tricks to match (Image: Helsinki University of Technology)




The Virtual Air Guitar project gives wannabe guitarists the chance to rock out (Image: Helsinki University of Technology)





Aspiring rock gods can at last create their own guitar solos - without ever having to pick up a real instrument, thanks to a group of Finnish computer science students.

The Virtual Air Guitar project, developed at the Helsinki University of Technology, adds genuine electric guitar sounds to the passionately played air guitar.

Using a computer to monitor the hand movements of a "player", the system adds riffs and licks to match frantic mid-air finger work. By responding instantly to a wide variety of gestures it promises to turn even the least musically gifted air guitarist to a virtual fret board virtuoso.

Aki Kanerva, Juha Laitinen and Teemu Mäki-Patola came up with the idea after being invited to develop a virtual instrument as part of their coursework. "The first thing that came to mind was an air guitar," Kanerva told New Scientist.

The resulting system consists of a video camera and a computer hooked up to an appropriately loud set of speakers.

A player then needs only to don a pair of brightly coloured gloves in order to rock out. Computer vision software automatically keeps track of their hands and detects different gestures, as a video of the system in action demonstrates (22MB, requires Windows Media Player and DivX codec for the visual aspect of the footage).
Frenetic strumming

The Finnish team created a library of guitar sounds based around the pentatonic minor scale – a progression commonly used for rock guitar solos – in order to create the right sound for their virtual instrument.

As a player moves their left hand along the neck of their virtual guitar, the computer will run through the scale. Holding it one place while strumming frenetically produces fret board tricks such as hammer-ons – where slapping a finger onto an already vibrating string produces a higher note – and blues bends, which give a distinctive rock twang. And a floor pedal can also be used to switch the system into mode that plays several different chords.

Kanerva says players can easily create unique air guitar style. "No two playing experiences are quite the same," he says. "When you're playing really hard you get a really nasty distortion sound which is great – but you have to work for it."

The project is currently being demonstrated at the Heureka Science Centre in Finland where it has been played more than 5000 times over the last month, Kanerva says. As a follow-up, the researchers are working on a version that will be compatible with a normal webcam and computer, thus giving wannabe rock stars the opportunity to practise their art in the privacy of their bedroom.

For Kanerva, who had to research different guitar playing tricks, the project has had another benefit. "I wasn't a guitarist before I started the project," he says. "But I am now."