The Open C7 Chord

The Formula of the Chord

The C7 chord, also known as the C dominant 7th chord, is a fundamental chord in many musical genres, including blues, jazz, and rock. This chord adds a bit of tension and richness compared to the regular C major chord. The formula for a dominant 7th chord consists of four intervals: the root (R), the major third (3), the perfect fifth (5), and the minor seventh (b7). For the C7 chord, the specific notes involved are:

• Root (R): C
• Major Third (3): E
• Perfect Fifth (5): G
• Minor Seventh (b7): Bb

In the open C7 chord, the voicing we play includes these notes distributed across the strings as follows:

• 5th string (A): C (R)
• 4th string (D): E (3)
• 3rd string (G): Bb (b7)
• 2nd string (B): C (R)
• 1st string (E): E (3)

How to Play the Chord

To play the open C7 chord using the A, D, G, B, and E strings, follow these step-by-step instructions:

1. Ring Finger: Place your ring finger on the 3rd fret of the 5th string (A string). This will produce the note C (R).
2. Middle Finger: Place your middle finger on the 2nd fret of the 4th string (D string). This will produce the note E (3).
3. Little Finger: Place your little finger on the 3rd fret of the 3rd string (G string). This will produce the note Bb (b7).
4. Index Finger: Place your index finger on the 1st fret of the 2nd string (B string). This will produce the note C (R).
5. Open High E String: Leave the 1st string (high E string) open. This string produces the note E (3).

Ensure your fingers are pressing down firmly just behind the frets to get a clear sound. The 6th string (E string) is typically not played in this chord voicing, but if it rings out, it still contains a note (E) that is part of the chord structure.

TAB Visualisation

Below is the tablature to help you visualise the C7 chord:

Tablature:

e|---0---| (Open String)
B|---1---| (Index Finger)
G|---3---| (Middle Finger)
D|---2---| (Ring Finger)
A|---3---| (Open String)
E|---x---| (Do not play)

By following these instructions, you should be able to play the open C7 chord effectively. This chord shape adds a rich and bluesy flavor to your playing, making it a valuable addition to your chord repertoire.