Have you ever yearned to play a violin like Leila Josefowicz or Paul Zukofsky but can't get beyond annoying scratchy squeals? Dr Dylan Menzies of the De Montfort University in Leicester, U.K., says that his O-Bow musical bow controller is much easier to master. A player selects notes from a bank of recorded violin sounds using a keyboard while the bowing hand strokes a traditional violin bow over an optical sensor. The result is pleasantly realistic.

Menzies actually set out to digitally emulate expressive bowed string sounds a few years back, and by December 2009 had built his first prototype. Based around the modification and playback of a single violin sample using synthesis script developed in Max/MSP, the system used an adapted optical mouse sensor to track the movement of the bow and add some expressive power to an otherwise rather dry and emotionless source sound. Unfortunately, as you can see (and hear) in the following video, the output is less than convincing.

A version of the system was transposed onto an Eigenlabs Eigenharp Alpha in July 2011, which moved keyboard control to a series of buttons/keys on the neck and placed a bowing sensor across the middle of the cello-like setup.

Now at the fifth prototype stage, and returning to the sensor/keyboard arrangement, Menzies seems to have ironed out many of the kinks. The sensor electronics and firmware has been completely reworked, the former now sitting at the bottom of a groove in polished copper tube stopped with wooden ends that lends itself to simple attachment to a microphone grip.

In addition to tracking horizontal movement, the sensor is able to approximately measure the distance of the bow above the saddle-shaped guide. At the moment, down force doesn't influence output, but the design could be extended to include this in the future – allowing the system to be adapted for different levels of ability.

Like the first version, the sensor is capable of tracking different types of bows, from classic violin bows to simple wooden sticks, and the angle of bowing affects the intensity of vibrato. The new setup is also capable of detecting the contact state and the rate of change to the bow distance above the saddle, which caters for more realistic bow release sounds.

Communication between the sensor and computer running the software is via USB-MIDI. The custom synthesis software has now moved away from its original Max/MSP home and been implemented using Kontakt script language from Native Instruments, allowing for more flexible and effective handling of a greater number of samples. Of course, players need not necessarily stay with the emulation of a violin. Since the system generates synthesized sound, the possibilities are limitless.

There's a short burst of the latest prototype in action below, which shows a distinct improvement in the sound produced by the system. The "feel" of the O-Bow has been improved, it's smoother and more responsive and can now keep up with rapid bowing.

Menzies reports that the O-Bow has attracted interest from a wide range of people including professional live musicians, studio producers, amateur musicians, educators, and disabled musicians. He told us that he's currently in the process of trying to bring the device to market. Meanwhile, more violin and cello sequences can be heard via the source link below.

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