This intriguing "Open Cm9" tuning transforms your guitar into a rich, resonant soundscape, perfect for jazz, blues, and cinematic compositions. It's a fantastic tuning for fingerstyle players and those looking to explore sophisticated harmonies with ease.

Technical Analysis

The open strings are tuned to D#3, G2, C3, D#4, A#4, D4. When strummed together, these notes form a beautiful C minor 9 chord (C-Eb-G-Bb-D), providing a melancholic yet full-bodied harmony without any fretting. The tuning essentially lays out the root (C), minor third (D#/Eb), perfect fifth (G), minor seventh (A#/Bb), and ninth (D) of the C minor 9 chord across the open strings.

The presence of a doubled minor third (D# on strings 6 and 3) adds depth and sustain. A key feature of this open tuning is the ability to play any minor 9 chord simply by barring all strings at a given fret. For instance, barring at the first fret yields a C#m9, and at the fifth fret, an Fm9. This makes complex chord progressions easily accessible.

The lowest note, D# on the 6th string, provides a strong bass foundation that, while not the root of the Cm9 chord, adds an interesting suspension and alternative harmonic flavor to the overall sound, pushing it beyond a simple minor chord.

While primarily designed for Cm9, other open chord voicings are within reach. For example, by selectively muting or fretting, you could imply variations around C minor, or explore chords whose roots are D#, G, or A#, utilizing the strong fifth and octave relationships present in the tuning.

How to Tune to Open Cm9

To achieve the Open Cm9 tuning from standard EADGBe, follow these steps for each string:

• String 6 (Lowest E): Tune down 1 semitones to D3#. This is a minor adjustment.
• String 5 (A): Tune down 2 semitones to G2. This is a moderate adjustment.
• String 4 (D): Tune down 2 semitones to C3. This is a moderate adjustment.
• String 3 (G): Tune down 4 semitones to D4#. This is a significant adjustment; please tune carefully and slowly to avoid excessive tension changes.
• String 2 (B): Tune down 1 semitones to A4#. This is a minor adjustment.
• String 1 (Highest E): Tune down 2 semitones to D4. This is a moderate adjustment.

Important Note: While none of the string movements exceed the recommended limit of 4 semitones up or down for standard string gauges, the 3rd string's adjustment of 4 semitones down is at the limit. Always tune carefully and be mindful of your guitar's neck and string tension. If you plan to keep your guitar in this tuning for extended periods, or if you feel any excessive looseness, you might consider adjusting string gauges for optimal playability and intonation.

Here are the notes for each string, from the lowest (6th) to the highest (1st):

• String 6: D3#
• String 5: G2
• String 4: C3
• String 3: D4#
• String 2: A4#
• String 1: D4