The altered scale is one of the most popular melodic devices in jazz, fusion, and other modern musical genres.
The 7th mode of melodic minor, the altered scale is used to solo over 7alt chords, as well as over 7th chords when you want to create tension.
By learning how to build, play, and solo with the altered scale, you give yourself the confidence needed to solo over dominant chords in a modern setting.
In this lesson, you learn the altered scale formula, fingerings, major and minor licks, 7alt chords, and a Blue Bossa guitar solo that uses this scale.
Altered Scale for Guitar (Click to Skip Down)
- Altered Scale Formula
- Altered Chords
- Altered Scale Shapes
- Altered Scale Licks Major ii V I
- Altered Scale Licks Minor ii V I
- Blue Bossa Guitar Solo
Altered Scale Formula
Before you take this scale onto the guitar, look at what the altered scale is and how it relates to melodic minor.
The easiest definition of this scale is:
The altered scale is the 7th mode of melodic minor and has the intervals R-b9-#9-3-b5-#5-b7.
This means, that if you have C melodic minor, and you play those same notes from B, you create a B altered scale.
Here’s how that looks.
- C Melodic – C D Eb F G A B
- B Altered – B C D Eb F G A
As you can see, both scales have the same notes, but they produce different sounds on guitar because of their interval structure.
- Melodic – R 2 b3 4 5 6 7
- Altered – R b9 #9 3 b5 #5 b7
Melodic minor is used to solo over m7 chords, and produces a mMaj7 sound over those changes.
On the other hand, the altered scale is used to solo over 7th chords, and produces a 7(b9,#9,b5,#5) sound over those changes.
Here are those two scales on the fretboard to compare their shapes and sounds on the guitar.
Click to hear altered scale primer 1 After you’ve listened to the above scales, play C melodic minor and B altered back to back to see how they relate on the fretboard.
Altered Chords for Guitar
Each of these chords contains at least one altered note, some have two, as well as a root, 3rd, or b7th.
After learning these shapes, take them to all 12 keys, and use them in your comping over tunes. Lastly, here are four 7alt chords on the top-4 strings. Notice that there isn’t a root in any of these chords.
This is because you only have four-notes and need to get at least one altered note in each chord.
Altered Scale Shapes
Now that you know how to build the altered scale and 7alt chords, you’re ready to learn how to play this important scale.
Here are two fingerings that you can learn, practice across the fretboard, and add to your jazz guitar solos.
After you’ve worked either these shapes with a metronome, put on the backing track below and jam over the C7alt chord.
So, make sure you take these shapes to your solos in your practice routine.
C7alt Backing Track C7alt Backing Track
Altered Scale Licks – Major ii V I
To begin using this scale in your guitar solos, here are three major ii V I licks that use the altered sound over each V7 chord.
When using altered over V7 chords in a major key, you create tension over that chord.
To ensure that this sounds like a choice, and not a mistake, you need to resolve that scale into the Imaj7 chord.
By doing so, you create the tension and release that’s essential when creating a jazz sound in your solos.
Here’s a backing track to practice each lick, as well as jam over as you take this scale to your own jazz guitar solos.
C Major ii V I Backing Track ii V I C Major Backing Track
The first altered lick features a classic Wes Montgomery style line over the G7.
Because this is an essential jazz phrase, it’s worth running in other musical situations.
Click to hear altered scale primer 2 The second altered line mixes leaps and steps to create tension over the V7 chord.
Notice how smoothly the Eb resolves to the D at start of the third bar.
This is the resolution you need to successfully apply the altered sound to a major ii V I.
Click to hear altered scale primer 3 In the final major lick, you resolve the tension before reaching Cmaj7 chord.
Here, the Ab resolves to the G at the end of the second bar, allowing you to leap to the D as no further resolution is needed.
Resolving tension over dominant chords takes time and practice.
But, studying lines teaches how to resolve onto the chord you’re on, as well as to the next chord in the tune.
As well, apply the Ab altered scale to the Ab7 chord in bar 10 of the progression.
Altered Scale Licks – Minor ii V I
You’re now going to apply this scale to a more diatonic setting, as you learn 3 minor ii V I licks on guitar.
In a minor ii V I, the V chord is always some variation of V7alt, so the altered scale is the perfect choice over that chord.
Because the chord is already altered, the notes in the altered scale sound diatonic as compared to a major ii V I, where they clashed with the V7 chord tones.
It still creates tension, but that tension matches the underlying chord, both of which resolve to the next chord in the progression.
Here’s a ii V I in Cm backing track that you can jam along with in the woodshed.
C Minor ii V I Backing Track ii V I Cm Backing Track
In this first lick, you apply the scale to the second half of the G7alt chord, with a Bdim7 arpeggio used to outline the first half.
Often, running scales over chords sounds predictable, so mixing them with arpeggios breaks things up and prevent your lines from sounding monotonous.
Click to hear altered scale primer 5 The second minor lick breaks up the scale into steps in the first half of the bar and leaps in the second half.
Again, by mixing steps and leaps, scales and arpeggios, you spice up your lines over common progressions.
In this case, you stick to notes from the altered scale for those leaps, as you focus on using only that scale over the entire V7alt chord.
Both of those phrases are common bebop vocabulary, and are worth studying further.
Click to hear altered scale primer 7 After you work on these these lines, put on the Blue Bossa backing track and apply these minor ii V I licks to a standard in your practice routine.
Blue Bossa Guitar Solo
Here’s a solo based on the jazz standard Blue Bossa. In this solo, you use the altered scale over both major and minor ii V I chord progressions.
Go slow when learning this study, take it four bars at a time before bringing those phrases together in your practice routine.
Applying scales to a musical situation often sounds stiff.
To prevent this, pay close attention to the chromatic notes, arpeggios, and other devices that make these lines sound musical.
While playing correct scales over chords is essential, it’s often the notes outside those scales that make a solo sound hip.
Check out the solo, study the lines, notice the chromatic notes and micro-phrases that grab your ears, and have fun with these lines in the woodshed.
To help you study this solo, and practice soloing over Blue Bossa on your own, here’s a backing track.
Backing Track Blues Bossa Backing Track
Click to hear altered scale primer 8