Drop C: C G C F A D
Now that you are in standard guitar tuning, tune your low E down to a D, so you are in drop D. Here is a drop D guitar tutorial if you need it. -
 http://www.howtotuneaguitar.org/tuning/drop-c/ - 11 KB
Guitar Drop Tuning Online
Sort out your drop tuning here with free Drop D, Drop C and Drop B guitar tuners and tips
 http://www.fretjam.com/drop-tuning.html - 23 KB
Drop C Tuning - Guitar Noise
Evan may be young but he does get his point across. Here's a lesson that introduces Drop C tuning and even includes a riff from Toxicity by System of a Down.
 http://www.guitarnoise.com/lesson/drop-c-tuning/ - 29 KB
Guitar Tuner @ HowToTuneAGuitar.org
Includes chord finder, guitar tuning methods, online guitar tuner, drop tuning guides, 10 tuning tips and secrets.
 http://www.howtotuneaguitar.org/ - 11 KB
Drop C tuning - Wikipedia, the free encyclopedia
The most commonly[citation needed] intended meaning of Drop C is CGCFAD. - or "drop D tuning transposed down a whole step", where the entire guitar is transposed to -
 http://en.wikipedia.org/wiki/Drop_C_tuning - 38 KB
C tuning guitar Video 5min.com
C tuning guitar - This video shows you how to tune your guitar to Drop C tuning. It is brought to you by Mike Deiure from Rock Guitar Power.
 http://www.5min.com/Video/Drop-C-Tuning---Guitar-29066283 - 384 KB
How to Tune Your Guitar in Dropped C - wikiHow
wikiHow article about How to Tune Your Guitar in Dropped C. - The difference between drop C and standard tuning is that drop C allows for the bottom -
 http://www.wikihow.com/Tune-Your-Guitar-in-Dropped-C - 49 KB
How to Tune a Guitar to Dropped C | eHow.com
How to Tune a Guitar to Dropped C. Dropped C guitar tuning is less well known than its close relative, dropped D tuning, but it is a commonly used -
 http://www.ehow.com/how_2042815_tune-guitar-dropped-c.html - 76 KB
Cleartone Drop Tune Electric Guitar Strings Drop C and more -
Find the lowest price on the Cleartone Drop Tune Electric Guitar Strings Drop C and more Guitar Strings at GuitarCenter.com.
 http://www.guitarcenter.com/Cleartone-Drop-Tune-Electric-G-Drop-C-786117-i1433164.gc - 98 KB
How to Drop C Tune a Guitar - wikiHow
wikiHow article about How to Drop C Tune a Guitar. - as you de-tune you lose tension in the neck so be careful when re tuning to standard or drop D or whatever as -
 http://www.wikihow.com/Drop-C-Tune-a-Guitar - 42 KB