Most beginners do not learn about note progressions and location on the fretboard. But if you read standard notation and want to play the note, then it is somewhat difficult on an ukulele.
There are 12 notes in an octave on a chromatic scale (piano is easy... just walk your fingers up starting at middle C and include the black notes. If you start on the C string, it is the same, but the notes are not colored or shaped differently. So you start open and that is a C, then fret 1 is the C# (first black key), next is D, D# E F F# G G# A A# and B. 12th fret is C again. But notes double up on different strings unlike a piano. So instead of playing the E on the 4th fret, you can play open on the E string. Instead of playing an A on the 5th fret on the E string, you can play the open A string. This is how most learn to play the C scale on an ukulele. So open C and D 2nd fret on the C string, open frets 1 & 3 for E F G on the E string, and open A, fret 2 and 3 for A B C on the A string.
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