A capo shortens the length of your guitar's strings so you can play in different keys while using simple open chord fingerings. If you follow these steps, you can use a capo effectively without experiencing tuning or buzzing problems.
1. Tune Your Guitar
The capo tends to expose out of tune guitars. For this reason, always check your tuning before you apply a capo.
2. Know Your Attachment Mechanism
There are several types of capos on the market today. Some are spring-loaded, others use an elastic type of material, and others are manually clamped to the fret board by the guitarist. Whichever type you prefer, take a second to understand how it is supposed to hold the strings down to the fret board. This video gives a quick demonstration of each type.
3. Dampen the Strings
Just before you place the capo on the fret board, use your strumming hand to dampen the strings as you would when you're silencing your guitar during a performance. Besides stopping any unintentional striking of notes as you're putting on the capo (which can be embarrassing in the middle of a concert), it pre-stretches the strings. This helps the guitar stay in tune when the capo's pressure is applied.
4. Place It Close
Always attach your capo just behind the targeted fret to help the guitar stay in tune. For example, if you want to capo your guitar at the second fret, don't put the capo right in the middle of the space between the first and second frets. Place it as close to the second fret (a hair behind it) as it can be. Don't put it on top of the second fret. Put it as close to it as possible without touching it.
5. Readjust as Necessary
After you've placed the capo in the desired position, make sure you test it with a few chords before you perform. This tests the clarity and volume, making sure your placement doesn't muffle or buzz the sound, and it tests the intonation. If your guitar gets increasingly out of tune the higher you place your capo, you may want to have your guitar's intonation fixed, which is a more involved procedure than simply tuning your guitar with a tuner. This video shows you how to fix intonation.
6. Transpose Keys
If you capo your guitar on the second fret, you raise your guitar's pitch two half-steps (or one whole step). That means a chord will sound one whole step higher than it sounded without the capo. If you finger a D chord, for example, what you will hear will be an E chord. If you finger an A chord, you will hear a B chord, and so on. The following video gives you a simple demonstration of how this looks and sounds.
7. Spare Your Tired Hand
If you're playing in a band or learning a song that is in an unusual key, like in D#, the capo gives you a quick and easy way to play in that key. The alternative to using the capo is using bar chords (like jazz guitarists often use) at the higher frets. However, if your hand isn't used to bar chords or if you've just played a marathon set and you're worn out, the capo can let you play easy open chords at higher keys and give your poor hand a well-deserved break from bar chords.
The Unique Sound of a Capo
The capo is not just a tool to make life easier for guitarists. It does something special for your guitar playing: it allows you to capture the full bodied sound of open chords at higher keys. Even if you know advanced chord charts and can play in any key without a capo, you may prefer the capo at times simply because of the unique sound it provides.