As with all chords, there is more than one fingering on the guitar for a C7 chord. The diagram below shows an alternative voicing for C7. The term "voicing" means the arrangement of notes in a particular fingering, with the notes arranged from the lowest to the highest. The C7 chord will always contain C (1), E (3), G (5) and Bb (b7)t but it is possible to arrange these notes in any order. The fingering shown below is voiced 3, b7, 1, 5.
Like the previous C7 shape, this chord is also moveable. The root note (C) in this voicing is on the 2nd string, so when moving the chord along the fretboard, whichever note is under your first finger becomes the name of the chord. This example moves between the chords C7, F7 and G7,
Here are six new moveable 7th chord shapes to go with the two C7 shapes you have already learnt. All these shapes are used in many styles, so be sure to memorize them well.
Notice that there are three shapes here for the E7 chord. It is also possible to find alternative fingerings for the other chords. Once you know which notes make up a particular chord, it is possible to arrange the notes in any order as long as the fingering is practical.
The following exercises will help you get comfortable with these 7th chord shapes. The first one uses the A7 form moved to a different position on the fretboard for each chord. The root note on the 5th string will tell you which fret to move to for each chord.
This one uses a G7 form moved between the same chords as the previous example. This time the root note is on the 3rd string.