What Is an Open String?

An open string is a string played without fretting it — no finger on the neck at all. In standard tuning, the open strings of a guitar are E, A, D, G, B, and E from thickest to thinnest. In tab notation, an open string is written as a 0.

Why open strings are your anchor notes

Every note on the fretboard is counted from an open string: the note at any fret is the open-string note raised by that many half steps. Know that the 5th string is A, and you know the 5th string's 3rd fret is C. That makes the six open-string names the first thing worth memorizing — there are classic mnemonics for EADGBE if they won't stick.

Open strings in chords

Chords that use open strings — the classic open chords like C, G, D, E, and A — ring louder and sustain longer than fretted shapes, because open strings vibrate along their full length. That ringing quality is also why alternate tunings like drop D exist: they move the open notes to fit the song.

Related terms

• Standard tuning — why the strings are E, A, D, G, B, E
• Open chord — chords built around open strings
• Natural note — the plain letter-name notes