Dominant 7 chords are tetrachords, ie, each of the 4 strings play a unique sound. That does not mean you must
'cover' each string with a finger since many 7 chords include one or more 'open' strings. But if you chose a form
of the chord which requires every string to be covered and you discover you are unable to 'span' all 4 string
positions, then you must not play the string you have left uncovered.
Now let's look at examples of 7 chords of varying shapes:
Each shape commences at the nut of your ukulele and with each progression up the neck you raise the chord's
sound by 1/2 tone. The shape remains unchanged,,,,
starting at fret 1 on C string the 7 chords rise as shown. Now you may continue along the neck of the uke as
high as you wish, and as you travel upwards you progresively raise the tone of the chord by 1/2 tone ie in our
example above, the next 7chord would be a C# (or Db) 7 and so on.
In this example the first '7' is on fret 1 of A string and it is called C7. Just as in the previous example we could
analyse all 4 notes in the chord and we would find they include the 1; 3; 5 and b7 notes of the scale used.
As in the first example this shape could be played progressively up the neck and each time the chord changes name
This is the next shape used. Notice that as you leave the nut of the uke you have to 'cover' the 'open' string
commencing at fret 1. In this example it is the E string which travels up the uke's neck behind the others.
This is the 4th form used to play 7 chords. It is the most troublesome shape for most of us to play as soon as it
leaves progresses from G to G# (Ab).
Hear what Curt Sheller has to say about chords in general and 7 chords in particular:
"There are many more open position chords available. Countless chord dictionaries, charts, books, software and
gadgets of all sorts are available with thousands of chords - BUT - these are not the answer. Even chord theory
does not offer any insight into unravelling the complexity of chord voicings.
Building on these basic open position chords is a start to expanding your chord vocabulary".
Your next step is to examine how you convert these dominant 7th chords into dominant 9th chords.................