Open A turns the guitar into a resonating chord: a single strum produces full harmony. Open-string overtones interweave, creating a vibrant, spacious timbre. On acoustic it sounds almost harp-like; with a slide — canonically bluesy.
Barre at any fret = ready-made major chord; lower the third by a half step = minor. Open strings serve as pedal bass, enriching chords with overtones. Keys related to the tuning's base chord sound especially full thanks to open-string resonance.
Scale fingerings are completely different from standard — fresh thinking is needed. But melodies over droning open strings gain modal depth: even a simple single-voice line sounds like a polyphonic texture.
Standard fingerings are useless — chords and scales must be relearned. Keys far from the tuning's base chord are awkward and sound dull. Skill transfer from standard is minimal: it's essentially a different instrument.
Right-hand skills, rhythmic feel, and musical ear transfer from standard. The left hand starts fresh: fingerings, scale boxes, and the note map are all different. In return you get the elegant logic of "barre = chord."
Slide (bottleneck) is the signature technique: gliding between fret-chords with vibrato. One-finger barre for rhythmic chords. Fingerpicking with alternating bass and melody. Natural harmonics — in open tunings they ring especially pure.
Set aside standard fingerings — they won't help. Start with open strings: play each, memorize the notes. Key rule: barre = major chord; build minor from there by adding one finger.
Play a I-IV-V progression with slide or barre — the entire cycle in three positions. Add single-note phrases between chord changes. Try fingerstyle: alternate bass on open lowers with melody on uppers.
Relearn notes on each string. Find octave pairs between strings — they become navigation beacons. Identify what notes the 5th, 7th, and 12th frets give on each string: that's your new fretboard skeleton.
Start with a 12-bar blues: three chords (I-IV-V) played with slide or barre in different positions. Even the minimum set sounds convincing immediately thanks to open-string resonance.