First chords: C, Am, F and G

C needs one finger, on the 3rd fret of the A string; with C, Am, F and G you can already play hundreds of songs.

Reading a chord box

A chord box is a picture of the fretboard standing upright, as if the ukulele were hanging on a wall facing you. The four vertical lines are the strings, G, C, E and A from left to right. The thick line at the top is the nut and the horizontal lines below it are the frets. A filled dot means press that string in the space just above the numbered fret line, and an open circle above the nut means play the string open. Numbers such as 0003 are a shorter way of writing the same thing: one digit per string, in G C E A order, giving the fret to press, with 0 for open.

Four shapes

C is 0003: put your ring finger on the 3rd fret of the A string and leave the rest open. The strings then sound G4, C4, E4 and C5, all notes of the C major chord (C, E, G). Am is 2000: middle finger on the 2nd fret of the G string, giving A4, C4, E4, A4, the notes of A minor (A, C, E). F is 2010: keep the Am finger and add your index finger on the 1st fret of the E string, which turns E into F and gives A, C, F, A, the notes of F major (F, A, C). G is 0232: index on the 2nd fret of the C string, middle on the 2nd fret of the A string and ring on the 3rd fret of the E string, giving G, D, G, B.

Press with the very tips of your fingers, close behind the fret wire rather than in the middle of the space, and keep the finger joints curved so they do not touch neighbouring strings. Your thumb rests behind the neck, roughly opposite your middle finger. If a string buzzes, press a little closer to the fret; if it sounds dead, another finger is probably leaning on it. Strum slowly with the side of your index fingernail, then pluck each string one at a time to check every note rings. Sore fingertips for the first week or two are normal and fade as the skin toughens.

Why four chords go so far

In the key of C major, C is the I chord, F is IV, G is V and Am is vi. The I, IV and V chords contain every note of the C major scale between them, so they can harmonise almost any simple melody in that key. Adding vi gives a minor colour. The order C, G, Am, F, or I, V, vi, IV, has been used in a huge number of pop songs, and the order C, Am, F, G, or I, vi, IV, V, was a favourite of 1950s ballads. The same four shapes will carry you through Twinkle, Ode to Joy and Row, Row, Row Your Boat in the coming units.

A short daily routine works better than one long session. Spend two minutes on each new shape: place the fingers, strum once, lift them off the strings, and place them again. The lifting and placing is the real exercise, because songs ask you to arrive at a shape, not to hold it. Then play the four chords in order with four slow strums each.