henry wrote:....But guitar players dont have sweetened tunings and strobo tuners and the rest......
We "sweeten" because we can. You don't have to, but there is a trade off as below and some ears are better at discerning the effect. Here goes
On steel guitar each note you play in a chord is related harmonically to the other notes at the same fret. The bar replicates the nut and we tune each note of the open tuning with reference to the tonic note at the nut (e.g. C in C6th, E in E9th). Thus:- play a Cmaj chord somewhere up the neck and the E and the G will be the perfect intervals of third and fifth to your tonic (C) so long as the 3rd and 5th are "perfect" in the
open tuning. Chords at every other fret have the same characteristic of being related to the tonic at that fret.
On standard guitar, chords are formed by placing fingers at different frets on different strings, so there is no relationship to the intervals at the open tuning; you aren't replicating a straight barre like the nut does. Therefore you don't get perfect 3rds and 5ths everywhere and need to compromise on each tone of the scale. All instruments where you cannot control the intonation, like piano, need this compromise if they are to play in many keys.
An example, the "true" note F# (7th in the scale of Gmaj and found in other "#" key signatures) is noticeably sharper to the ear than the "true" note Gb (needed in the key of Db, so unlikely to bother us much). Since one piano key, concertina button, guitar fret, harp string etc. has to do the job of both notes, the pitch is tuned half way between - i.e. Gb slightly sharp, equalling F# slightly flat; but not spot-on for either. All other notes on the keyboard, because each will need to sound ok in different keys, are a similar half-way compromise.
