Six-string ukuleles are getting quite hard to find, and it’s a shame because they sound particularly ukulele-like, at least to my ears. In this recent article, I tell you how to convert a regular 4-string ukulele into a six-stringer with conventional tuning, but I found that there are a lot more tunings you could use, and some sound just as sweet as the standard. In this article, I go through the math and give you some samples.
The “standard” (let’s call it that way) 6-string ukulele is tuned like the regular soprano, concert, or tenor instrument, except that the 1st and 3rd strings are doubled up in octaves. Thus, instead of a G4-C4-E4-A4 tuning (4th to 1st), you get G4-(C5-C4)-E4-(A3-A4), where the string pairs in parentheses are placed in close proximity so they can be played as a single string. It sounds both “full” and “sweet”, probably due to the fact that the pitches of the six strings are still within a fairly small interval (15 semitones). But why double up precisely the 1st and 3rd strings, and not the others? I think one way to come up with this result is the following rule:
“Take the highest-pitched string and double it up with a string one octave below. Take the lowest-pitched string and double it up with a string one octave above.”
This way, the pitches of the added strings fold over the initial overall interval, making the resulting interval as tight as possible. It seemed to me that this rule could be applied to ukulele tunings other than the standard reentrant on the 4th string, in order to obtain 6-string tunings that would sound different but also quite sweet. In this previous post, I discussed the 4 different tunings that span a minimum interval. If we now apply the above rule to each of them, we get the following:
- Starting from the G4-C4-E4-A4 standard tuning, we get the standard G4-(C5-C4)-E4-(A3-A4) tuning for a 6-string uke, with 1st and 3rd doubled up, spanning 15 semitones.
- Starting from the G4-C4-E4-A3 Lili’U tuning, we get the (G3-G4)-C4-E4-(A3-A4) with 1st and 4th doubled up, spanning 14 semitones.
- Starting from the G3-C4-E4-A3 “cuatro” tuning, we get the (G3-G4)-C4-(E4-E3)-A3 with 2nd and 4th doubled up, spanning 15 semitones.
- Starting from the G3-C4-E3-A3 “barbershop” tuning, we get the G3-(C4-C3)-(E4-E3)-A3 with 2nd and 3rd doubled up, spanning 16 semitones.
In deciding the order within each doubled-up group, I used an additional rule: “The first string in each group to be played in an upstroke should be on a linear scale as far as possible; reversed for the 4th which is to be picked by thumb” in order to facilitate fingerpicking.
Now, elementary combinatorics tells us that there are two more ways to pick two strings out of a set of four, namely, 1st and 2nd, and 3rd and 4th. This creates two more 6-string tunings that cannot be created using the general rule:
- Starting from the G3-C4-E4-A4 low-G tuning, we get G3-C4-(E3-E4)-(A3-A4) with 1st and 2nd doubled up, spanning 17 semitones.
- Starting from the G3-C4-E4-A4 low-G tuning, we get (G4-G3)-(C5-C4)-E4-A4 with 3rd and 4th doubled up, also spanning 17 semitones. This happens to be the tuning of a standard 8-string “taropatch” ukulele, except that strings 1 and 2 are not doubled up (in unison) as they are in the 8-string uke.
As a table:
| 4-str. tuning | Name | derived 6-str. tuning | Interval (semitones) | Doubled strings |
| G4-C4-E4-A4 | standard | G4-(C5-C4)-E4-(A3-A4) | 15 | 1st, 3rd |
| G4-C4-E4-A3 | Lili’U | (G3-G4)-C4-E4-(A3-A4) | 14 | 1st, 4th |
| G3-C4-E4-A3 | cuatro | (G4-G3)-C4-(E4-E3)-A3 | 15 | 2nd, 4th |
| G3-C4-E3-A3 | barbershop | G3-(C4-C3)-(E4-E3)-A3 | 16 | 2nd, 3rd |
| G3-C4-E4-A4 | low-G | G3-C4-(E3-E4)-(A3-A4) | 17 | 1st, 2nd |
| G3-C4-E4-A4 | low-G | (G4-G3)-(C5-C4)-E4-A4 | 17 | 3rd, 4th |
Does it sound good? As you can imagine, playing this with real instruments means a lot of different ukuleles to make, since the majority of these combinations are not to be found in stores. What I did in order to get an idea of figuring out how they might actually sound is make virtual instruments on a MIDI guitar as I showed in this article (strings 1 to 4), run the MIDI output through MIDIFlow on an iPad, so some strings could be raised or lowered an octave, and even duplicated at a shifted pitch, and the result (on channel 7) piped to the nylon string guitar patch on SoundCanvas (iOS version), and then to a guitar amp. It’s not perfect, but it does give an idea. I’m also throwing in the recording for a real 6-string ukulele, from this article, so you can try to extrapolate how the synthesized sounds might sound in reality. All samples consist of playing the following chords twice: C-E7-A7-D7-G7-F-Bb-G-C.
Here’s the real 6-string ukulele, with standard tuning:
The same standard tuning, but synthesized as described above (all the rest that follow are also synthesized):
Starting from Lili’U tuning:
From cuatro tuning:
From barbershop tuning:
From low-G tuning, doubling up 1st and 2nd:
From low-G tuning, doubling up 3rd and 4th: