Inverted chords consists of chords in which the notes have changed order and the tonic (the root of the chord) is no longer the bass note. Some get confused when they see a chord like C/E printed. What it means is that the E note has changed position in the chord to become the bass note. The practical meaning of this is that the chord is played inverted. The C chord with the notes C, E and G are instead played in order as E, G and C.
Why make an untidiness like this out of it, you may wonder. The inverted chords are especially common for piano players: changing the order of notes in a chord can minimize the distance of movement over the keyboard then switching from one chord to another. For guitarist's the inverted chord has not this function, but is giving possibilities to enrich the sound and make smooth transitions in chord progressions. This group is familiar with slash chords.
Common inverted chords
1st inversions (C/E)
2nd inversions (C/G)
Chord progressions with inverted chords
If you want some guidelines, here are some progressions you can use. This is a couple of sequences that includes inverted chords that gives you a sense of one important application of these chords:
G - D/F# - Em
(Instead of the usual D we are positioning the F# as the bass note and by being between G and E it’s fulfill a special musical movement along with the chord changes.)
A - A/C# - D
(This time we just switch the bass note of the same chord from A to an C# – that are placed between A and D in the scale – before moving on to D.)
In this third example the movement starts with the inverted chord:
E/B - Am - G
You should be able to find other variants now as you know the method.
All inversions of major chords
Diagrams and information of first and second inversions:
Some inverted 7th chords
The chords in the four last diagrams are all dominant sevenths with alternative bass notes. A chord progression you can try is:
C - G7/B - Am7
Note that the bass note remains at the second string throughout the whole sequence (the low E-string shouldn't be played at all).