See the "Five Unusual Capos" video review

Everyone knows what a capo does, right? Well, yes and no. While most capos press down all six of a guitar's strings at a given fret, some models are designed for less mundane tasks. Thanks to players like David Wilcox, Harvey Reid, Stephen Bennett, and Chris Proctor, partial capoing techniques—which can allow you to simulate the sound of alternate tunings and create suspended chord voicings while using standard-tuning chord shapes—are more popular than ever, and several new products have been introduced to meet the demand.

I recently had a chance to check out four capos designed to clamp select strings, rather than all six at once. I also spent some time with the Weaseltrap Harmonic Capo, which offers a unique way to expand a guitar's tonal palette.

KYSER SHORT-CUT AND SHUBB C7B

Kyser: $20; kysermusical.com. Shubb: $20; shubb.com

Kyser Short-Cut

Shubb C7B

TRANSPO CAPO

$49; transpocapo.com

Transpo Capo

The Transpo capo combines two capos into one. It is basically two Kyser-style spring-loaded capos connected about two inches apart, with one side a standard capo that clamps down all six strings at once, and the other a three-string partial capo like the Kyser Short-Cut and Shubb C7B. This configuration creates an Esus4 shape on strings three, four, and five, and simultaneously capos the entire guitar up two frets below the partial capo, allowing you to create the same effect as the Short-Cut and C7B but in different keys up the neck. The Transpo can also be flipped around and used as a standard capo, but because of its wide design, this only works on the second fret and above (on short-scale guitars, it may only work on the third fret and above).

The Transpo capo essentially functions as advertised—enabling rich and ringing sus4 chords in various positions. There are some limitations, though. When I used it on a Taylor 914c with a 251/2-inch scale, the distance between the two capos was too large for use above the seventh fret. And while having two capos attached to each other was convenient for several applications, you could accomplish the same thing with two separate capos. However, if Esus4-shape partial capoing up the neck is your thing, the Transpo offers a fast and easy way to get there.

THIRD HAND CAPO

$13; thirdhandcapo.com

Third Hand Capo

Featuring a design originally conceived by guitarist Harvey Reid, the Third Hand Capo has been around for many years, and it remains unique in its ability to capo any single string or combination of strings.

Based to some extent on the design principles of an elastic-band capo, which is held in place by elastic tension, the Third Hand uses six individual hard rubber discs that rotate around a metal rod to stop the strings. Like other elastic-band capos, it's a bit clumsy to install, and the fact that the strap encircles the neck makes it difficult to fret open strings behind the capo. However, the flexibility of this ingenious design makes the Third Hand ideal for experimentation. For the adventurous player, it's hard to beat the Third Hand—no guitarist who's into partial capoing should be without one.

BOB KILGORE'S HARMONIC CAPO

$35; weaseltrap.com

Bob Kilgore's Harmonic Capo

The brainchild of guitarist Bob Kilgore, the Harmonic capo is a unique tool for accessing a guitar's 12th-fret harmonics while simultaneously playing the fretboard in a standard fashion. The Harmonic capo uses six individual rubber pads (adjustable in height and spacing) in a simple mechanism that attaches to the guitar's neck at the 12th fret with an elastic strap. Rather than fully pressing down on the strings, the Harmonic capo's pads are designed to lightly touch the strings in the same way you'd use a finger to play a harmonic.

When installed and adjusted properly, the act of fretting notes below the capo drops the string away from the pad and allows these notes to sound as usual, while open strings sound the harmonic. Because of the tight tolerances needed to make this work, I had to adjust the capo from scratch every time I installed it, leading me to believe that unless it was used for the first tune in a set, it would be difficult to use onstage. The capo also won't work on guitars with neck/body joints at the 12th fret.

These limitations aside, the Harmonic capo is an ingenious device that allows you to create scores of unique sounds, such as arpeggios of harmonics over moving bass lines. It does take some fooling around to discover the tunes and techniques that will work best, but if you're willing to invest some time, you'll be rewarded with unique sounds that would be difficult or impossible to achieve in any other way.

THE WRAP

Each of these five capos has something unique to offer. The Kyser, Shubb, Transpo, and Third Hand are great for guitarists who want to get alternate-tuning sounds without relearning the fretboard or retuning the guitar, as well as players who enjoy experimenting with nonstandard guitar techniques. The Harmonic capo is in its own category and opens a whole world of new possibilities for adventurous players. Note to significant others: each of these units would make a great gift for the guitarist in your life!