In music, guitarists often use octave shapes to play rhythm guitar parts, riffs, and lead lines.
An octave is the distance between one pitch and another with half or double its frequency (see Guitar Theory For Dummies, Chapter 2). In other words, it’s a higher or lower version of the same pitch. You can also think of an octave as the same pitch in a different register. On the guitar fretboard, octaves follow certain spacings and shapes that you finger in a few different ways.
Whenever your index finger is on a note on string 6, you can reach over two strings and up two frets to play the same note an octave higher. You can do the same thing when your index is on string 5.
When your index finger is on string 4 or 3, you play the octaves by reaching over two strings and up three frets. You need to reach up an extra fret in these cases because of the way the second string is tuned.
A common guitar technique involves strumming across the strings to sound the octaves together. To do this without sounding unwanted pitches on the unused strings, you need to mute strings with your fretting-hand fingers. You do this by fretting the octaves with your fingertips and then leaning your fingers back so they lightly touch and dampen the neighboring strings. When your index finger is on string 5, 4, or 3, place it on the string so that the tip bumps into and mutes the string above.
Don’t get discouraged if your octaves sound messy at first. It takes time and practice to move around the fretboard and play octaves correctly. The more you do it, the more you’ll develop the right touch to do it well, so stick with it and be patient with the process.
The best way to practice playing octaves on guitar is to play songs that use them. The following ten songs make good use of octave shapes.
Ten Guitar Songs That Use Octaves
- “Killing in the Name” Rage Against The Machine (Interlude)
- “My Sharona” The Knack (Main riff)
- “Fire” Jimi Hendrix (Opening riff)
- “Third Stone From the Sun” Jimi Hendrix (Theme)
- “Immigrant Song” Led Zeppelin (Main riff)
- “The Wanton Song” Led Zeppelin (Main riff)
- “All the Small Things” Blink 182 (Gtr. 2 Chorus, Interlude)
- “Everlong” Foo Fighters (Pre-chorus)
- “Boulevard Of Broken Dreams” Green Day (Guitar Solo)
- “Bumpin’ on Sunset” Wes Montgomery (Opening lead)
How Many Octaves on a Guitar?
From the low E string to the 24th fret on the high E string on a 24-fret guitar, the range of a guitar spans four octaves. But since most guitars only have 22 frets, the range spans just short of four octaves. You can play each note from the musical alphabet in three octaves on the guitar fretboard. Since twelve notes are in the chromatic scale, you can play thirty-six octaves on a guitar (3×12=36). That’s note A in three octaves, note A# in three octaves, note B in three octaves, and so on until you’ve completed the chromatic scale. But, wait! There’s more. You can play the same note in the same octave in different locations on the guitar fretboard. For example, the A note at the second fret of the third string can also be played at the seventh fret of the fourth string and the twelfth fret of the fifth string. These notes have the same frequency (A=220hz), and are not in different octaves (as in A=110hz, A=440hz). So, tracking notes and octaves on the guitar fretboard is more complicated than other instruments such as the piano. Still, where would rock and roll be without guitar? I wouldn’t want to know.
On a 24-fret guitar, the range from the low E string to the high E string at the 24th fret spans four octaves, but most guitars with 22 frets fall just short. You can play each musical note in three octaves on the fretboard. Additionally, you can find the same note in the same octave in different positions on the fretboard grid, such as the A=220hz note at different frets on different strings, all with the same frequency (2nd fret of the 3rd string, 7th fret of the 4th string, 12th fret of the 5th string). The challenge of navigating notes and octaves on the guitar fretboard starkly contrasts with instruments like the piano, where notes are linearly arranged from left to right, each frequency occupying a single, distinct location.