Welcome to the latest installment of Chord by Chord, a series designed to build your understanding of harmony and the fretboard. Last time, we went over the I–vi–IV–V7–I in the key of G major. This time, we’ll add the viidim chord after the IV for a more involved progression.

The Work

You should already be familiar with the I, vi, IV, and V7 chords, so to get the viidim (F#dim) chord, just start on the seventh note (F#) of the G major scale (Example 1) and then add the notes A and C—a stack of minor thirds (Example 2).


Example 3 gives us the I–vi–IV–viidim–V7–I in G using open chords. If the four-note F#dim is too difficult to finger, just eliminate the note on string 1. Notice that the notes of the F#dim chord (F# A C) are the same as the highest three notes of the D7 (D F# A C) that follows.

Example 4 shows the progression using barre chords and Example 5 does the same, just higher up the neck. Remember that you don’t need to play all five or six notes of each barre chord—again, try just the bottom or middle four.

In Example 6 you’ll find a bunch of compact voicings on just the top three strings. Remember, these are great for when you’re playing with another guitarist who’s using fuller voicings, or a keyboardist or bassist. Notice the smooth movement between chords—for instance, the G and Em chords share the same two top notes.

The Result

You should now know how to play a I–vi–IV–viidim–V7–I progression using various voicings in the key of G major. Practice strumming or fingerpicking this new progression on your own. In the next lesson we’ll explore one more chord progression before moving on to other chord types.