256. THE TRIAD OF CHOICES WHEN IMPROVISING A MELODY

The simplicity of triad of factors for the melodic action is  mainly the next three factors

1) The triad of polarity (qualitative) of a melodic move (ascending, descending, rotating stationarily or isocratic), The relevant theme variation here is inversion

2) The  quantitative  triad of the character of the move :Chromatic (2nds) , Melodic (3rds) ,Harmonic (4th, 5ths or more than 8ths). The relevant theme variation here is expansion-contraction

3) The rhythmic pattern of repetitions or translations . The relevant theme variation here is translation.

The keys to a nice flow of improvisation as expressed in many cultures folk music are 

Simplicity in the harmony (triads of harmonic pairs of chords or triads of chords or only a pair of chords or a single power-chord)
Simplicity in melodic themes 
Simplicity in rhythmic and pitch variations of the melodic themes and repetitions


IF THE CENTRAL  ENTITY IN HARMONY IS THE TRIAD CHORD THE CENTRAL ENTITY IN MELODY IS THE MELODIC THEME AND IN PARTICULAR THE OVERSIMPLIFIED VERSION OF SIMPLE MELODIC MOVE BY AN INTERVAL AS  TRACED IN SIMPLIFIED WAY BY THE SIMPLICIAL SUBMELODY.

Based on the above, the themes in the simplicial sub-melody as simple moves are of two polarities up (+) or down (-) and of three sizes Chromatic (symbol C) by intervals of 2nds, Melodic (symbol M) by intervals of 3rd and Harmonic (symbol H) by intervals of 4th, 5th, 8th or higher. Then the progression of the simplicial melodic themes in the song will have a symbolic form like E.g.

H(+)M(-)H(-)M(+)C(-)M(+)H(+).......etc

The translation/transposition  of a simplicial melodic theme retains its cahracter as chromatic , melodic or harmonic.
The inversion of a simplicial melodic theme inverses the + to - andthe - to +
The expansion/contraction of a simplicial melodic theme e.g. an expansion changes a chromatic to a melodic or harmonic and a melodic to an harmonic. A contraction changes an harmonic to a melodic or chromatic and a melodic to a chromatic.


MAINLY MELODIC IMPROVISATION WITH CHROMATIC DECORATIONS
There is a type of improvisation where the  main and most often (at least 1/2 of the time) size of steps in the Improvisational "walking" is the intervals of 3rds in other words "meloding walking" , and in particular alternating major and minor 3rds. Then about 1/3 of the time we move with chromatic steps of intervals of 2nds, and particular when going up or down we oscillate around a note with an interval of 2nd (chromatic embellishments) and less often (less than 1/3 of the time) with harmonic intervals in other words  intervals of 4ths, 5ths or larger than 8ths.

Such type of improvisation is quite often in folk Irish music or early New Orleans jazz. This is the cae also with Andes improvisational folk music with Zampona pan-flutes.

This type of improvisation works well in diatonic scales where there is maximum number of triad chords made from alternating intervals of major-minor 3rds. On the other had in chromatic minor scale (harmonic minor, double harmonic minor, melodic minor , parachromatic etc) the "walking" with intervals of 2nds is more convenient as there not many triad major or minor chords .


Such improvisation are to be contrasted with the usual "improvisational walking" e.g. of Stephane Grappelli which is mainly with steps by intervals of 2nds.

Similarly improvisational counter-melodies in Greek folk Bouzouki music which are mainly with steps by intervals of 2nds.

When making a melodic improvisation the triad of choices are the next 3 (similar to the triad of choices in chord-progression improvisation  of making  a chord transition which is chromatic melodic or harmonic. The mutation or rotation may be considered  a 4th decision but it essential a restart of the previous process.

1) TRANSLATE UP OR DOWN THE MELODIC THEME, CHROMATICALLY, MELODICALLY OR HARMONICALLY 

2) INVERT THE MELODIC THEME CHROMATICALLY, MELODICALLY OR HARMONICALLY

3) EXPAND-CONTRACT THE MELODIC THEME WITHIN THE SCALE.

4) ROTATE IMPROVISATIONALLY IN PLACE OR CREATE A NEW MELODIC THEME (MUTATION) IN PLACE , OR UP OR DOWN BY AN HARMONIC INTERVAL (4TH OR 5TH) OR INTERVAL LARGER THAN AN OCTAVE.

255. THE Gm7 MINOR (Bb AEOLIAN MODE) TENOR GUITAR AND CORRESPONDING BARITONE OR TENOR UKULELE AND BOUZOUKI

THE PREFERENCE OF THE B FLAT SCALE

It seems that in various cultures there is a systematic preference of the Bb major scale and its minor mode G in various chromatic versions natural G minor, harmonic G minor, double harmonic G minor, etc

1) Most of the old centuries folk Greek songs (dimotika) seem to be ton Bb scale

2) Most of the Greek rebetika seem to in G chromatic minors  and D chromatic minors

3) The natural scales of Trumpet and clarinet is in Bb.

4) It seems that early new Orleans Jazz (that utilizes trumpet and clarinet) is in Bb scale (e.g. see Tuba skinny https://www.youtube.com/watch?v=wk64II0TGCk )

What is the real reason? Difficult to say. But the next video finds the reason on the pineal gland the the link of the soul to the body https://www.youtube.com/watch?v=8vP72lFnrDk

Thus a guitar with privileged scale  the Bb instead of the standard G major would be advantageous to play such music.

And as 4-strings (or 4-double strings) tenor guitar version this Bb major scale tuning would be

(from lower pitch to higher)      F3-Bb3-D4-G4

it is an open Gm7 tuning.

The next 3 pictures are from a baritone ukulele tuned in this way. 
A baritone ukulele  usually has scale length of 48 cm, which for the E4 string of the standard guitar is about the note A4.
 Actually I have subtracted the second double string from the higher 3 pairs of strings and have left it only to the lower pitch pair of strings to make the sound more sweet.

An ordinary tenor size with 4-double strings ukulele can also have very well a Bb major or G minor tuning as follows

There is also the Bb major or G minor tuning as follows

(F2:F4 Bb2:Bb4, D3:D4, G3:G4)

or 

(F3:F4 Bb3:Bb4, D3:D4, G3:G4)

4-DOUBLE STRINGS TENOR GUITAR (GUITAR-LELE)

(The range is about the vocal range of a female contralto singer)

A tenor guitar  has scale length usually 58 cm which is about the F#4 at the E4 string of the standard guitar. 

With the nylon strings the G minor or Bb major tuning  in other words 

(F2:F4, Bb2:Bb3, D3:D4, G3:G4) 

is supported as follows:

So for the G4 of the 1st pair, I use an E4-guitar nylon string. For the G3 of the 1st string I use an nylon G3-string of the guitar. For the D4 of the 2nd pair, I use a nylon B3-string of the guitar. For the D3 of the 2nd pair, I use a nylon D3-string of the guitar. For the Bb3 of the 3rd pair, I use again a nylon G3-string of the guitar. For the Bb2 of the 3rd pair, I use a nylon A2 string of the guitar. For the F4 of the 4th pair, I use a nylon A4-string of the tenor ukulele . And for the F2 of the 4th pair I use a nylon E2-string of the guitar. 

This (F2:F4, Bb2:Bb3, D3:D4, G3:G4)  tuning is supported also with usual guitar metal strings

So for the G4 of the 1st pair, I use an E4-guitar metal string. For the G3 of the 1st string I use a metal G3-string of the guitar. For the D4 of the 2nd pair, I use a  B3-string of the guitar. For the D3 of the 2nd pair, I use a metal  D3-string of the guitar. For the Bb3 of the 3rd pair, I use again a metal G3-string of the guitar. For the Bb2 of the 3rd pair, I use a   A2 string of the guitar. For the F4 of the 4th pair, I use a  E4-string of the guitar . And for the F2 of the 4th pair I use a  E2-string of the guitar.

Of course we may as well have this Bb or G minor tuning with single strings

(F3, Bb3, D4, G4)

Such a Bb tuning can very well apply to the 2/3 children 6-string guitar of about 58 cm too, with the full 6-string version

(G2, C3, F3, Bb3, D4, G4)



As alternative the Bb tuning can be in the normal position open Gm7 tuning

G3-Bb3-D4-F4

Which can very well apply for a Bb 4-single strings Bouzouki

 The above 4-course Bb guitar can be extended to 6-courses or 6-strings Bb guitar as in post 273.

THE UKULELE-BOUZOUKI-PANDURI TUNING on 6-strings

This tuning sometimes is used in the instrument Dobro too.

We apply the 3M-3m-4-3M-4  tuning in intervals

This is best realizable in shorter an 2/3 or 1/2 children guitar :

The F3-Bb3-D3-G4  part is a 4-string Greek Bouzouki or a ukulele in Bb major

The Bb2-X-F3-Bb3 part is a 3-string Greek Bouzouki in Bb major

The Eb2-Bb2-F3 is a low tambouras or saz with privileged scale the Eb major.

Some further advantages of this Bb 6-string guitar tuning are 

1) At the 4 higher strings all the chord-shapes and chords of the standard guitar can be played without any note missing. Thus we reduce all well-known guitar chord playing in the higher 4-strings

2) Nevertheless, in the lower 3 strings, it plays also the 2-frets triad-chords of 3 strings of a panduri

3) In the 5th 3rd 2nd strings it plays all the tunes of a Greek 3-strong bouzouki, including the isocratic with two strings playing as drone an interval of 5th Thus it combines playing with ancient tunings that require strings tuned at  intervals of 5th (melodies orientation) and more modern tunings (chords or harmonic orientation)

4) It is an open minor 7nth or major 6th tuning.

5) It has two intervals of 8th (2nd-5th, and 3rd-1st strings) and one interval of 5th (6th-4th strings) which allows for nice isocratic improvisations.

6) It has chord triads with all 3 inversions in all 4 rows of consecutive strings 1st-2nd-3rd (Ionian mode) , 2nd-3rd-4th (Aeolian mode) , 3rd-4th-5th ( Ionian mode) , 4th-5th-6th (Ionian mode) 

We should mention though that this improvement is not as advantageous as the fully melodic-harmonic guitar tuning described in post 90. The only reason we describe the current tuning is that it preserves the 2/3 of the learned guitar on the standard tuning while it allow for more chord triads and advantages described above. 

254. THE PANDURI TUNING AND OTHER ALTERNATIVE TUNINGS OF SAZ

5) And I have converted a saz (https://en.wikipedia.org/wiki/Ba%C4%9Flama 79 cm scale length)  to an Harmonic Threechord (with tuning   G3:G4, B3:B3, E3:E4:E4  or F3:F4, A3:A3, D3:D4:D4.

Notice that the highest string E4 is octaved one octave lower by E3, while the lowest string G3  is octaved by one octave higher.  This instrument  has a very fine and sweet sound and can be played with the most swell and easiest way compared to the other conversions, because of 

1) the narrow width of the neck 

2)  very low height of the (movable) frets 

3) very low tension of the strings 

4) very small diameter of the strings of such instruments. 

I consider this instrument a divine sound and easiness  when playing it!

Of course I have set the movable frets only to the 12-tone equal temperament  Bach scale and have get rid of the other additional movable frets. 

We notice that the rule ofthe octave strings in the pairs is that of teh half-baritone. In other words in the high triple string E3:E4:E4, the octave string E3 is lower, while in the lowests pair G3:G4, the octave string is the G4 which is higher. The main notes are the (G3, B3, E4).

Again an important advantage of this tuning of the 3-groups of strings Saz is that all the three inversions of a major or minor chord exist as triads (3-notes chords) as the shapes of the guitar chords D, A, E, inherited on the 3-pairs of strings only. (see DAE system post 3). So for any solo that one plays, he can quickly try a major or minor chord in one of the above 3-inversions or shapes that contains the particular note of the melody (even as root of the chord shape). The simplicity of an instrument when it is adequate harmonically and melodically ,sometimes can contribute as  major factor for easy and fruitful improvisation.

Finally other optimal tuning are the harmonic tuning that is alternating intervals of major and minor thirds, that make a 3-notes chord (see also Harmonic tuning of the guitar in post 90 ) Here it would be 

G3G4-B3B3-D4D4D4 or G3G4-Bb3Bb3-D4D4D4 or A3A4-C4C4-E4E4E4 or 

A3A4-C#4C#4-E4E4E4 etc  Such tuning has the highest density per a number of frets of major or minor triad chords.


Some Russian bass or alto Balalaikas have such tuning inherited from Russian (gypsy) guitar open tuning

PANDURI TUNING FOR SAZI (IN THE RANGE OF TAMBOURAS AND BOULGARI)


These tunings have less range than the tunings by 5ths , but also other advantages that we describe here

These PANDURI tunings are not only mainly for playing arpeggios and simplicial submelody, when another ,usually wind , instrument is playing the solo but advantageous, as we explain below when the Saz is playing solo too.

For solos, the tunings below have the characteristic that we can easily-readily play the 2nd or 3rd voice on the other 2 strings. In addition as the strings are  close and differ only at an interval of 3rd, and as most melodies have a span of 1-2 octaves, then all of the  melody  can be played in  one only of the 3 strings (courses) which is quite intuitive in its linear pitch order, as in harp or panflute (except here chromatically not diatonically).

This tuning is the open G major chord or F major chord.

G2G3-B3B3-D3D4D4   or F2F3-A3A3-C3C4C4  

Because the D3D4D4 course of strings has two D4 it sounds like D4 finally rather than like D3! So the final sound is like G2-B3-D4.

It has 3 inversions triads for each major o minor chord but the normal form is the simplest. 


Such tuning (see also post 90 about the harmonic tuning of the guitar ) has the next advantages:

1) the highest density per a number of frets of major or minor triad chords in normal position .
2) They are easier for chords in normal position rather than for inversions(Compared to the standard tuning o 3-double strings bouzouki which is easier for chords in  inversions rather than in normal position).

3) The solos are in closer frets to the fingers and we do not need to shift the hand a lot to find the appropriate note.

G3G4-B3B3-D4D4D4 or G3G4-Bb3Bb3-D4D4D4 or A3A4-C4C4-E4E4E4 or A3A4-C#4C#4-E4E4E4 etc  Such tuning has the highest density per a number of frets of major or minor triad chords.

We give the  calculations of the right frets positions fora  saz  which has variable frets,of scale length 79 cm. We calculate the distance of each fret from the upper or lower end of the string (scale) , so that approximation errors are not added when realizing these positions. In these calculations the angle of the string relative to the surface ofthe fretboard is not included. If included the calculations might have very very small modifications. (For the formula for the  calculations see post 1) 

FRETBOARD DIMENSIONS	79	SCALE LENGTH IN CM
Number of fret	Lemgth from lower string end till fret	Multipler	Length from upper string end till fret
1	74.5661,	0.056125687	4.4339
2	70.3810	0.109101282	8.6190
3	66.4308	0.159103585	12.5692
4	62.7023	0.206299474	16.2977
5	59.1831	0.250846462	19.8169
6	55.8614	0.292893219	23.1386
7	52.7262	0.332580073	26.2738
8	49.7669	0.370039475	29.2331
9	46.9737	0.405396442	32.0263
10	44.3373	0.438768976	34.6627
11	41.8488	0.470268453	37.1512
12	39.5000	0.5	39.5000
13	37.2830	0.528062844	41.7170
14	35.1905	0.554550641	43.8095
15	33.2154	0.579551792	45.7846
16	31.3512	0.603149737	47.6488
17	29.5916	0.625423231	49.4084
18	27.9307	0.646446609	51.0693
19	26.3631	0.666290036	52.6369
20	24.8834	0.685019738	54.1166
21	23.4868	0.702698221	55.5132
22	22.1686	0.719384488	56.8314
23	20.9244	0.735134226	58.0756
24	19.7500	0.75	59.2500

253. SOME ALTERNATIVE TUNINGS TO PUERTO-RICAN CUATRO

The next pictures are from a Puerto-Rican Cuatro as 4-double strings instrument, with the previous tuning that makes it a guitar-lele.

We may utilize a E4 guitar string for the A4 of the A3:A4. We may utilize a D3  guitar string for the A3 of the A3:A4. We may utilize a  A2 or better for lower tension a D3 guitar string for the E3 of the E3:E4. We may utilize a B3 guitar string for the E4 of the E3:E4. We may utilize a G3  guitar string for the C4 of the C3:C4. We may utilize a  A2 guitar string for the C3 of the C3:C4. We may utilize a D3  guitar string for the G3 of the G3:G2. We may utilize a E2  guitar string for the G2 of the G3:G2. With the above choice of strings, and given that the scale length of this shorter guitar (baritone ukulele and the quatro with 48-52 cm scale length) is about at the A4 note of the e4 string of  a normal guitar, the strings are either exactly at the intended tension given the scale length or one note above or below the normal tension! 

Some advantages of this kind of tuning where in all the pairs  the two strings are one octave apart are the next  

1) it covers larger range of octaves than the tuning of an ordinary (tenor) ukulele! 

2) It also gives the opportunity with sufficient skill in the right hand fingernails, to play only the higher strings of each pair or only the lower strings of each pair moving therefore in two different octaves the same melody or harp-ism. 

3) Furthermore when singing, the instrument supports the voice in two octaves rather than one octave which makes singing more well supported by the instrument thus easier and more comfortable and accurate! 

While a tenor ukulele is about the range of a human mezzo soprano, and a charango-ukulele, about the range of a soprano human voice, the above tuning for a baritone ukulele or a Quatro it is about the range  Contralto human voice. 

252. SOME ALTERNATIVE TUNINGS TO UKULELE AND TENOR GUITAR

ARPEGGIOS AND DEA SYSTEM OF 4-STRING INSTRUMENTS (SEE POST 67)

For the 4-string (double or simple strings) instruments of post 67, that are most of the ethnic music instruments , the chord shapes theory simplifies to the DEA instead of the CAGE of the 6-string guitar. Similarly the arpeggios of the chords, although are not identical with the shapes of the chords in a 6-string guitar, for the above 4-string instruments , they are identical with the chord shape! Thus knowing the chords means knowing their arpeggios of them too, which gives immediately a way of easy improvisation along a chord progression! 

In this post we shall show also how to convert some of  the above instruments to an harmonic Tetrachord of various sizes.

1) I have a 4-double plastic string tenor ukulele, for small sizes (43 cm scale length) tuning (G4:G3,  C5:C4 , E4:E4, A4:A4) .
The 43 cm for the E4 string of a standard guitar is about the note B4.
 It has the advantage of finding each note one wants when improvising easier. And practically as it has only 4-pairs of strings (as all other Harmonic tetrachords of course) it is almost impossible to make a mistake , when playing as almost all 4-notes can be a type of not very unusual  extended chord! We must let the fingers dance in the improvisation, which is advised to utilize all 4-pairs of strings, in a harping (finger picking) , strumming or soloing. And even a if an undesirable  dissonance appears, it is softened by the octave distance of the strings in the pairs.  (see e.g. https://www.youtube.com/watch?v=a6sM9zWc9Tg)

The next tuning makes the tenor 8-string ukulele to sound more bass and sweet:
(G4:G2, C5:C3, E3:E4, A3:A4)! Notice that we do not alter the high pitch strings in each pair but we alter the second string to be one octave lower! For the high pitch strings we use the usual strings of the ukulele. For the lower pitch strings we use nylon strings of the guitar. For the A3 of the A3:A4 pair a D3 or G3 guitar string. For the E3 of the pair E3:E4, a A2 guitar string or D3 . For the C3 of the pair C5:C3, we use a E2 or A2 string of the guitar. And for the G2 string of the pair G4:G2, again a E2 string of the guitar. 

There is also the Bb major or G minor tuning as follows

(F2:F4 Bb2:Bb4, D3:D4, G3:G4)
or 
(F3:F4 Bb3:Bb4, D3:D4, G3:G4)



Finally other optimal ways of tuning are the harmonic tuning that is alternating intervals of major and minor thirds, that make a 3-notes chord (see also Harmonic tuning of the guitar in post 90 ) Here it would be 


A3A4-C3C4-E4E4-G4G4  


Such tuning (see also post 90 about the harmonic tuning of the guitar ) has the next advantages:

1) the highest density per a number of frets of major or minor triad chords in normal position .
2) They are easier for chords in normal position rather than for inversions(Compared to the standard tuning o 4-double strings ukulele which is easier for chords in  inversions rather than in normal position).

3) The solos are in closer frets to the fingers and we do not need to shift the hand a lot to find the appropriate note.


2) I have converted a TENOR 4-PAIRS OF STRINGS GUITAR AND THE GUITAR-LELE  (58 cm scale length) to tenor 4-double string  Harmonic Tetra-chord or contralto guitar (tuning (D4:D3, G4:G3, B3:B3, E4:E4) , which is my favorite size. Notice that it could be tuned also as  (D3:D3, G3:G3, B3:B3, E4:E4). For the strings I used he standard strings of a 12-string guitar. But it is a bit moe hard to play, as it is of 58 cm only compared to the 66 cm of the classical guitar.so one could use slightly different strings. E.g. for the G3 of the G4:G3 pair instead of the standard 0.61mm string  one could use a 0.56 mm string of the Bouzouki , which in the standard tuning of the 4-string bouzouki would be the F3 string. And for the D3, string of the pair D4:D3,  instead of the standard 0.81mm D3-string of the guitar ,  it could be used the 0.61mm Guitar G3-string, or the 0.71mm Bouzouki C3-string, or the 0.76mm 12-string guitar metal covered E3-string which is put as high secondary to the 6th lowest E2-string. 
This tuning of a tenor guitar, gives a sweet and high frequencies sound, as the lower two strings are "octaved" at an octave higher.It is suitable for small instrument bodies.

 4-DOUBLE STRINGS GUITAR (GUITAR-LELE)
(The range is about the vocal range of a female contralto singer)
An alternative way to tune and play it, is by utilizing nylon strings and tune the 1st string as A. In more detail I use the tuning (G2:G4, C3:C4, E3:E4, A3:A4),  which is appropriate with nylon strings for a tenor guitar which has scale length usually 58 cm. 

So for the A4 of the 1st pair, I use an E4-guitar nylon string. For the A3 of the 1st string I use an nylon G3-string of the guitar. For the E4 of the 2nd pair, I use a nylon B3-string of the guitar. For the E3 of the 2nd pair, I use a nylon D3-string of the guitar. For the C4 of the 3rd pair, I use again a nylon G3-string of the guitar. For the C3 of the 3rd pair, I use a nylon A2 string of the guitar. For the G4 of the 4th pair, I use a nylon A4-string of the tenor ukulele . And for the G2 of the 4th pair I use a nylon E2-string of the guitar. If we want to have this tuning with metal strings (and scale length 58 cm) then one solution is to utilize Saz metal strings (For the instrument of saz see below) 

With the same nylon strings the G minor or Bb major tuning is supported in other words 

(F2:F4, Bb2:Bb3, D3:D4, G3:G4)

This tuning is supported also with usual guitar metal strings

So for the G4 of the 1st pair, I use an E4-guitar metal string. For the G3 of the 1st string I use a metal G3-string of the guitar. For the D4 of the 2nd pair, I use a  B3-string of the guitar. For the D3 of the 2nd pair, I use a metal  D3-string of the guitar. For the Bb3 of the 3rd pair, I use again a metal G3-string of the guitar. For the Bb2 of the 3rd pair, I use a   A2 string of the guitar. For the F4 of the 4th pair, I use a  E4-string of the guitar . And for the F2 of the 4th pair I use a  E2-string of the guitar.

Of course we may as well have this Bb or G minor tuning with single strings

(F3, Bb3, D4, G4)

Such a Bb tuning can very well apply to the 2/3 children 6-string guitar of about 58 cm too, with the full 6-string version

(G2, C3, F3, Bb3, D4, G4)

The above tuning is best done on a baritone ukulele which usually has scale length of 48 cm, thus one can utilize directly guitar nylon strings , without stretching the strings at all above their usual tension. 
 If we want to tune the baritone ukulele in its normal tuning it is
(D4:D3, G4:G3, B3:B3, E4:E4). If we tune in the normal tuning to make it sound more vivid, with normal tension of strings of the guitar or tenor ukulele (the baritone ukulele has usually 2/3 of the normal tension only) we may use for the pair E4:E4, a pair of B3:B3 of the guitar (with the smaller size of the baritone ukulele sound exactly as E4E4), for the pair of  B3:B3, we use a pair of G3:G3 of the guitar strings, for the G3 of the pair G4:G3, we use a normal G3 string of the baritone ukulele, for the G4, of the pair G4:G3, we use a A4 string of a tenor ukulele, which because of the difference of the sizes in the baritone it can be tuned easily to sound G4. For the D3 of the pair D4:D3, we use a normal D3 string of the baritone ukulele, for the D4, of the pair D4:D3, we use a E4 string of a tenor ukulele, which because of the difference of the sizes in the baritone it can be tuned easily to sound D4.


The same if it is used a 51cm -52 cm scale length Puerto-Rican Cuatro where only the higher  4 pairs of strings are used at all. 

The next 3 pictures are from a baritone ukulele