Todd Rose wrote:
Michael's got a point there. The point being, as I see it (not sure if this is exactly what Michael meant):
When you have a capo on, say at the 5th fret, and then fret a note at the 8th fret, that string is now being pressed down to the frets in two places. This will cause it to produce a slightly higher pitch than if it were being fretted at the 8th fret without the capo. So, intonation is affected somewhat by the capo. That is, if you get the capo on the 5th fret and the notes are spot-on at ADGCEA (implying a well-intonated guitar and a well-fit capo, properly placed), any notes you now fret at higher frets will not intonate quite as well as they do without the capo. They'll be slightly sharp. So, in theory at least, to get the best possible compensation/intonation with the capo on, the guitar SHOULD be retuned after putting on the capo, making very small adjustments whereby some or all of the open notes ADGCEA (again, just using the 5th fret capo as an example) are made slightly flat in a compromise tuning for the benefit of the fretted notes.
If the guitar normally intonates very well, the capo is a good fit, and the player puts it on properly, so that the capoed "open" strings are in tune, such retuning is probably splitting hairs and not really necessary. As stated, a guitar is not a violin; there's always some dissonance, and it's up to the player to make it sound good. That said, one more general comment: part of making a guitar sound good is using one's ear to to tune it as well as possible, whether it has excellent or not-so-good intonation. I consider the player's skill in tuning the instrument to be the final step in compensation (actually, as it's been said, the FINAL step is in the actual playing). Electronic tuners are never as good as a good ear, and no two guitars will each intonate optimally (each guitar to the best of its own potential) if tuned to exactly the same open string pitches. Stated conversely, every individual guitar, on any given day, needs to be tuned slightly differently, by ear, to intonate as best as it possibly can. Even if you aren't being overly perfectionistic about tuning, approaching tuning with this mindset will make your guitar play more in tune every time you pick it up, turn off the electronic tuner, and tweak it a little by ear (mostly by checking various octaves all over the neck). The vast majority of players, in my observation, could benefit from more ear training and more education in tuning their guitars - myself included, though I've studied music, guitar, and ear training for nearly 30 years.
exactly