Guitar Open Tuning Correlations
There are 12 keys of music. Using numbers to represent the 8 notes that makes up their respective major scales, it is easier to understand the tunings. These three are the most common open tunings mainly because they can be achieved using a standard guitar string configuration (EADGBE) They are called "open" because they produce a major chord when strummed. A major chord requires 3 notes (1,3,5) from the major scale.
Vestapol Tuning: 151351 aka Open D (DADf#ad)
Spanish Tuning: 515135 aka Open G (DGDgbd)
Open C Tuning: 151513 (CGCgce)
Any grouping of these three notes creates a "triad" (basic 3 note chord). The musical distance between two notes is called an "interval" and when these triads are strummed, the different configurations produce their own unique "voice". Two notes played at the same time are called "double stops". They can be thought of as a little chord fragments.
Notice the 3 major chord variations found in the above tunings:
135, 351, 513
A major chord contains three intervals:
Example: 513 = 5-1, 1-3, 5-3
I routinely use these tunings on Cigar Box Guitar:
3 string: 151/GDg and 513/ADf# (Key of G and D)
4 string: 5135/Dgbd (Key of G)
With a little study of the above 6 string tunings, it is easy to realize my CBG tunings are based on these tunings. Of course, by keeping the same tone configurations, I can restring or retune to any key.
CD2 (Open G - 6 string - DGDgbd), CD 4 (G5 tuning - 3 string - GDg), and CD5 (Open G - 4 string - Dgbd) comprise a comprehensive course of applying Open G on three different instruments. Exploring in this way really opened up the fingerboard for me. After exploring CBG, I never looked at the full 6 string fingerboard the same way again.
About the 3 String Rural Primative Banjo
A standard 5 string banjo is often tuned to Open G (gDgbd). Disregarding the high drone g string, using a 4 string CBG, I usually use Dgbd tuning (CD 5). This is also the highest strings of the full 6 string tuning on guitar for Open G - DGDgbd (CD 2).
This banjo simply reduces the standard banjo tuning down by elimating the two highest strings. gDgbd into gDg. I use this GDg tuning on 3 string CBG too (CD 4). The only difference is the (banjo) tone created by having a high drone g instead of a lower g on CBG.
(Note: I am tuned up a full step to aEa on this banjo. Due to the fact the relationships between the strings are staying the same, all the finger positions will be the same.) A fundamental understanding of musical theory can go a long way to seeing the various possibilities of playing in different keys. (CD 7)
In a future video, I will present a more traditional approach by alternating the high drone a and E strings while playing a melody line on the first a string. Keep in mind, 5 string banjos are usually fingerpicked (Earl Scruggs 3 finger style) or use the claw hammer method. 4 string tenor or plectrum banjos are played with a flat pick.
Another interesting possibility would be an altered 4 string banjo. A high g drone and Dgb. Dgb is the same string relationship from the major scale (513) as the ADf# tuning I use on CD 6 for 3 string CBG. Using the movable chord method that this tuning offers could make for a very versatile instrument. (Note: This instrument could be tuned up a whole step to aEac# and all the fingering positions would remain the same.)
Enjoy your practice. http://youtu.be/o8PKhCCcA44
I made a cbg tutorial dvd a few years ago, its free with my cbg purchase: http://www.jagshouse.com/cbg/cbgvideo.html