Playing a bar chord requires that one finger holds down more than one string at the same time. This is not an easy thing to do at first and usually needs a certain amount of practice. Once you are able to play them, though, bar chords are incredibly useful. The beauty is that when you can play a particular bar chord shape you can move it to any point along the fretboard to produce the same type of chord at different pitches.
Many bar chords are based on the shapes of the open chords we’ve already seen. To move the chords up the neck the first finger (usually) of the left hand is used as a ‘bar’ across the open strings and so takes the place of the nut (the thing at the top of the neck with slits to keep the strings in place) in open chords.
There are a few common bar chord shapes that, once mastered, will lend a great amount of versatility to your playing.
This shape is often referred to as an ‘E shape’ bar chord. You’ll notice that the fingering pattern on frets 2 and 3 of this F chord are the same as frets 1 and 2 of an open E chord (with different fingers.) So the whole shape has been moved up one fret and the first finger is used to bar the 1st fret, taking the place of what would be the nut in an open E chord. It can be played on any fret along the neck. The name of the chord will be the same as the root note being played on the 6th string (which happens to be F in this example.) You can refer to the fretboard section if you need to find out the note positions.
The same principal applies here except this is an Em shape. It’s been moved up one fret with the first finger now barring the strings on the 1st fret. Again this can be played at any fret position along the neck and will take it’s name from the root note played on the 6th string eg. at the 3rd fret this would be Gm.
The same idea again here. This chord is shown barred at the 5th fret just to demonstrate the point of movability, taking the shape of the open E7 chord and shifting it up the neck. At the 5th fret the 6th string produces an A note, hence the chord in this example is an A7.
A m7 bar chord shape is the same as this but without the 2nd finger being applied to the fretboard.
This bar chord takes it’s shape from an open A chord and so, as you may expect, is commonly referred to as an ‘A shape’ bar chord. The example shown here is a C chord as the root note in this shape is played on the 5th string (A) which produces a C note at the 3rd fret. The shapes of the open Am, A7, Am7 and Amaj7 can all be played as bar chords at any fret on the neck to give these types of chords at different pitches. Note that the 6th string (low E) is not usually sounded when playing this shape of bar chord.