Cb minor pentatonic is one of the most useful scales a guitarist can learn. It's the moody, bluesy five-note scale behind countless rock and blues solos, here starting from the note Cb. The name looks odd, and some of the notes are written with double flats. Don't let that worry you. By the end of this page you'll know what the notes are, why they're spelled that way, and exactly where to put your fingers.
"Pentatonic" simply means five notes. The notes of Cb minor pentatonic are:
Cb, Ebb, Fb, Gb, Bbb
Each note has a job, described by its number in the scale:
A "b" after a letter means flat, or one fret lower. A "bb" (double flat) means two frets lower. So Ebb sounds the same as D, and Bbb sounds the same as A. Cb itself sounds the same as B, and Fb sounds the same as E.
In other words, Cb minor pentatonic sounds exactly like B minor pentatonic, and that's how most players think of it. Theory spells it with double flats so that every letter name gets used in order without repeats. If you've already learned B minor pentatonic, you already know this scale. Same frets, same sound, just a different label.
On guitar, a half step (H) is the distance of one fret. A whole step (W) is two frets. The minor pentatonic follows this pattern of gaps:
W+H - W - W - W+H - W
Starting on Cb, here's how it plays out:
Try it on one string. Put your finger on the 6th (low E) string at fret 7, which is Cb. Then play frets 10, 12, 14, 17 and 19. You've just walked up the whole scale on a single string, and those wide gaps are why it sounds so open.
This scale comes from the Cb natural minor scale: Cb, Db, Ebb, Fb, Gb, Abb, Bbb. The pentatonic version simply removes two notes, the 2nd (Db) and the 6th (Abb).
Those two notes are the ones most likely to clash with chords underneath you. Take them out and what's left is almost impossible to play "wrong." That's why it's usually the first scale guitarists learn, and why it's the classic sound of rock and blues soloing.
The character note to listen for is Ebb, the minor 3rd. Play Cb, then Ebb, and hear that sad, serious quality. Then try bending up to Bbb, the minor 7th, and let it hang. That note gives you the tough, bluesy cry you hear in so many solos.
One more useful fact: Ebb major pentatonic uses the very same five notes. It just treats Ebb as home instead of Cb. Same notes, brighter mood, depending on which note you resolve to.
Because this scale comes from Cb natural minor, it fits nicely over that key's main minor chords:
A simple progression to jam over is the minor blues-style i - iv - v:
Cbm - Fbm - Cbm - Gbm
On the guitar you'd play those shapes as Bm, Em, Bm and F#m. Record yourself strumming it slowly, a bar on each chord, then loop it and solo over the top. Aim to land on Cb when the progression returns to Cbm, and you'll hear everything click into place.
In standard tuning, the root note Cb lives here:
The most popular starting point is the box shape anchored at fret 7 on the low E string. Use your first finger for fret 7 and your other fingers for the frets above it:
Notice that Cb appears three times in this one shape: low E fret 7, D string fret 9 and high E fret 7. Those are your "home" notes. Whenever a phrase feels lost, head for one of them.
Spend five minutes playing the box shape slowly, up and down, saying each note name out loud. Then put on your Cbm - Fbm - Cbm - Gbm loop and improvise using just three notes: Cb, Ebb and Bbb. Limiting yourself like that forces you to make music with rhythm and feel, which is where great solos really come from. Add the other notes once those three feel like old friends. Have fun with it.
For the bigger picture, read The Minor Pentatonic Scale.