K wrote:Anyone else enjoy open chord tunings? Obviously open G is a classic (DGDGBD) and makes you sound like Keef, but I've been using open A recently (EAEAC#E) to get a nice Delta blues sound. Even though I could just use a capo I prefer the open A tuning. T5D may have an explanation for that.
Everything that's played on open G can also be played on open A so you don't have to relearn the fretboard.
Open A has the strings at a significantly higher tension.
and enter in the notes for each string. There's a formula from physics that I don't remember well that relates the frequency of a string to its tension. (See Mersenne's Law at https://en.wikipedia.org/wiki/String_vibration
Holding string length and string material constant, frequency, f, is proportional to the square root of tension, t. A better way to put this for our purpose is that f^2 = t. If you raise the pitch a whole tone, the frequency goes up by about 12 percent (details: 2^(2/12) approx 1.12). Square that and you see the tension, t, goes up by about 25 percent (1.12^2 approx 1.25).
Your ear hears this tension as a "brighter", "cleaner" and potentially louder sound with a well-defined overtone series and less non-harmonic content. To paraphrase this in simpler terms, higher tension strings can give you more volume and emphasize the note in the abstract, for example, an A. Lower tension strings in comparison can emphasize things that are unrelated to the note in the abstract, such as plectrum or finger style technique.
One problem you need to consider, however, is that the increased tension isn't good for your guitar neck. You may be going from about 50 lbs of tension to 63 lbs for light gauge strings when you go from open G to open A
If you're using heavy or medium gauge strings, be careful.
Regarding dropping the low E to D or even C, a lot of guitars don't sound good and have lots of intonation problems with this. I sometimes use this as a way of testing out acoustic guitars to see how well made they are.
Alternate tunings that are lower (and that have lower tension) such as Nick Drake's "Pink Moon" tuning mentioned above are useful because the lower tension allows the string's non-harmonic sounds unrelated to the overtone series come out. You can really hear Drake's right hand technique in his playing. (Ditto with Joni Mitchell.)
For a long time, I couldn't figure out why, but then I found out that his strings are usually at lower tension. This also worked for Skip James as well, who used a open D minor tuning, DADFAD, for "Devil Got My Woman". People were particularly mystified by his guitar sound prior to his appearance at the Newport Folk Festival in 1964 and showed how you could get it from this tuning.