In the popular music and standard song field, sheet music for many years included a vocal line, piano accompaniment (sometimes mirroring the melody), and graphically-represented ukulele chords above the vocal line. These were often shown with a box graphic, four vertical lines representing the strings of the ukelele, and five or six horizontal lines representing the frets on the fingerboard.
Dots placed on the verticals, and between the horizontals, indicated the placement of the fingers on the fingerboard to achieve the ukulele chords voicing required. Typically, these ukulele chords never moved out of ‘first position’ (the low end of the fingerboard) and could easily be played by all standards of player. The practice of showing ukulele chords persisted, in the view of some commentators, well beyond the era where the instrument was in popular use, and became redundant after that point. Some music publishers switched to showing guitar chords with a similar box graphic (but with six vertical lines for the guitar strings), and some switched to showing chords by name rather than symbol.
If using a baritone ukulele, which shares its tuning with the top four strings of a standard guitar, a player can read the graphical guitar chords directly as ukulele chords, but not otherwise, as other models of ukulele have different tunings. If ukulele chords are shown by symbol – Cma for C major, or Gmi for G minor, for instance – any ukulele player who knows the chords on their instrument by name can execute them on this basis, rather than playing them from specific voicings or from standard notation. An instruction to play C major followed by G major, for instance, functions equally well as an instruction to play them as guitar chords or ukulele chords (or on any other chordal instrument, such as a piano or vibraphone).