Drop C tuning
The Drop C tuning is mainly used in heavy metal and can give you a real heavy and bassy sound (a song example is Nirvana's "Something in the Way"). A useful device to implement together with this tuning is palm muting.
Here is how you tune the guitar: CGCFAD (see also CADGBE Tuning) From standard tuning you tune down the lowest string two whole steps and when one whole step for the rest (see the picture).
It's very important that you turn the tuning pegs in a direction that decrease the string tension and not the opposite; otherwise, it's a great risk you break the strings and possible damage the guitar.
Power chords
C5
D5
E5
F5
G5
A5
B5
Comments
The chords above demand obviously not much. You could see the similarities to normal power chords and you should also to a high degree use them in a similar way.
An interesting thing is that you can play barre chords as normal, despite the changed tuning, and they will sound good. In some cases, it will also sound good and slightly different from normal with open chords. Since five of six strings have been change with the same proportions (one tone down), it will still sound pretty much as usual, but slightly different. Try for yourself and see.
Some other chords that can be used in Drop C tuning in shorted notations:
Cmaj9: 030000
Cadd9: 075780
D: XX2100
Dm: XX2000
E: XX4322
Em: XX4222
F/C: XX0003
G11: 7 8 10 0 0 X
CADGBE tuning
Related to Drop C tuning is the CADGBE tuning. Notice that only the bass tone is tuned different from standard tuning in the latter case. Sometimes CADGBe is also referred to as Dropped C tuning.
Chords
C
D
Dm
E
Em
F/C
Gmaj7/D
G7/D
Since only the lowest string differs from standard tuning, many open chords could be played just as normal, but you could also choose to use alternatives like the D major and D minor in the diagrams above.
Some other chords that can be used in CADGBe tuning in shorted notations:
C6: 002010
Cmaj7:022010
Em7/D: XX0000
Fmaj7/A: X03210
G6/D: 222000
Am/C: 0 0 2 2 1 0
B/D#: 32440X
Progressions
Some suggestions of chord progressions in this (CADGBe) tuning:
C - Cmaj7 (032000) - Em11/D (202000) - Cadd11 (033010) - C
Sometimes it will sound great including the low C tone, sometimes it will not.
For more progressions, see The Alternate Tunings ebook.
Alternative Drop C tunings
Besides the CGCFAD version presented here, there are some “alternative Drop C tunings”, which are foremost CGCGCE and CGDGBE.
This was an introduction about chords in the Drop C tuning, see also Drop B tuning.