Few things can stop a show dead in its tracks like taking the time to change your tuning. Some upscale players carry a different guitar for each tuning, along with a roadie to keep them in tune, but for most of us this is not an option. Designer Trev Wilkinson has come up with another solution: a self-tuning bridge that stores up to six different tunings, recallable at the touch of a button.

The ATD HT 440 bridge looks surprisingly normal, but under the hood are precision gears and microprocessors worthy of the space shuttle. Each string is attached to a capstan rotated by an individual motor and gearbox. A slim hex pickup sits between the back pickup and the bridge, informing the computer whether each string is tuned to the proper note. On one end of the pickup is an LCD display, on the other a tiny button that activates the 9-volt battery- powered unit.

A quick touch to the power button sends you to a chromatic tuner—not the fastest I have used, but adequate. The thing is, once you have initially tuned each of the six presets to their tunings, you will not often need to use it, as the whole point of the bridge is that it tunes itself.

Holding down the power button for a second or two brought up the tuning preset numbers. Each push of the button moved to the next preset. Once I was on the preset I wanted, I had to strum the strings within three seconds. The capstans then rotated appropriately until the guitar was in the new tuning. A second or third strum might be necessary, but then I was done—in a fraction of the time that it would take to turn the headstock tuners and check each string against an electronic tuner. Though not quite fast enough to switch tunings mid song— unless I arranged a musical interlude by my bandmates—it is quick enough to keep a set moving from tune to tune, without having to cart extra instruments.

How well did it tune? Very well indeed. I cycled though each of the factory tunings, from standard to DADGAD, and found no need to do any fine tuning once the bridge worked its magic. Even more amazing was that after I twisted the trussrod and adjusted saddle height of the host guitar to suit my playing preference, the bridge readjusted the tuning perfectly.

After multiple readings of the manual, I was able to program my own tunings—a process that involved retuning the guitar with the headstock machines, then selecting one of the six preset slots for the new tuning.

For now, the bridge is only available in the test model Fret King Super-Matic guitar ($1,599 street), but there is talk of retrofit possibilities down the line. In the meantime, if multiple tunings are a part of your performance, I highly recommend checking out the versatile Super-Matic with the ATD HT 440 self-tuning bridge.

KUDOS Retunes guitar quickly and accurately.

CONCERNS Some learning curve to programming new tunings.

CONTACT Wilkinson, (973) 335-7888; info@fretking.com