7 and 8-String Guitar Tuning

A 7 or 8-string guitar is not a different instrument. It is a normal guitar with one or two extra strings added below the low E, tuned to continue the same pattern of fourths. Everything you already know about chords, scales, and standard tuning still applies — you just have more room at the bottom.

Where it gets interesting is the physics. Notes that low need the right string, the right scale length, and a setup that accounts for them. Get any of those wrong and the low string sounds like a rubber band.

Standard Tunings

The low B on a 7-string is the same pitch as the lowest string on a 5-string bass. The low F♯ on an 8-string is lower than a 4-string bass's open E. These are genuinely low notes, which is why gauge and scale length stop being optional.

Common Alternate and Drop Tunings

• Drop A (7-string): A E A D G B E. The low B drops to A for one-finger power chords, the extended-range equivalent of drop D.
• Drop E (8-string): E B E A D G B E. The low F♯ drops to E, one octave below the 6th string. Very common because it makes the lowest string consonant with the rest.
• Whole-step down (7-string): A D G C F A D. The entire guitar down a tone for a darker, heavier standard.
• All-fourths (7-string): B E A D G C F. Replaces the major third between the top two strings with another fourth, which makes scale and arpeggio shapes fully symmetrical at the cost of familiar chord grips.

String Gauges That Actually Work

The number one mistake with extended-range guitars is a low string that is too light. It will feel floppy, buzz against the frets, sound muddy, and refuse to intonate. As a starting point:

• Low B, 25.5" scale: .059–.064
• Low B, 26.5–27" scale: .056–.060
• Low F♯, 27–28" scale or multiscale: .070–.080

Longer scale lengths let you use a slightly lighter gauge at the same pitch because the extra length adds tension. If you are tuning even lower than standard, go heavier again, or move to a baritone or multiscale instrument built for it.

Tuning One Accurately

Very low strings are the hardest thing for any tuner to read, including this one. The fundamental frequency is weak, the harmonics are strong, and cheap tuners often lock onto an overtone and show you a note an octave too high.

1. Use the 7-string tuner or chromatic tuner, which are set up to track the low range.
2. Pluck the low string softly, closer to the neck than the bridge, and let it ring for a full second before reading. A hard pick attack near the bridge feeds the tuner harmonics.
3. Mute the other strings with your palm so nothing sympathetic confuses the reading.
4. Check the octave number if your tuner shows one. The low B on a 7-string should read B1, not B2.
5. Tune up to the note, not down to it, so the string settles under tension.

Once the low string is stable, tune the remaining six exactly as you would a standard guitar — they have not changed. The whole appeal of extended range is that everything above the new string stays completely familiar.