In hard rock and heavy metal, very often the solo section will just stay in the one key, and so you can use the one or two basic scales throughout. Sometimes though, you may come across key changes or shifts in the tonality that you will need to negotiate. For this column, I’d like to show you a simple way of dealing with key changes whist using a scale-based approach to soloing. To do this, I’ve chosen to look at the basic opening chord progression of the classic Steve Vai track ‘Taurus Bulba’ from his 1996 album ‘Fire Garden’. 


Here is the basic 16 bar vamp that opens ‘Taurus Bulba’. Although on the recording this is played as a crunching riff with distortion, if the harmony is stripped-back we actually get a series of I-II chord progressions – first in E Phrygian Dominant for eight bars, and then four bars of D Lydian and then C Lydian respectively. The I-bII (E-F) progression implies E Phrygian Dominant, and since it lasts for eight bars, we can consider this to be the primary tonality/key. However, the following D major and C major chords don’t belong to the key of E Phrygian Dominant. What happens here is that the song briefly modulates to D Lydian via a I-II (D-E) chord loop, and then changes to C Lydian with another  I-!! (C-D) progression.

Hear Exercise 1


As mentioned, the primary tonality for ‘Taurus Bulba’ is E Phrygian Dominant. Phrygian Dominant (1-b2-3-4-5-b6-b7) is the fifth mode of the Harmonic minor scale (1-2-b3-4-5-b6-7). Exercise 2 is a useful three note per string fingering for E Phrygian Dominant in tenth position.

Hear Exercise 2


Phrygian Dominant will get you through the first eight bars of the progression, but what about the subsequent eight bars and the change to D Lydian and then C Lydian? Sure, you technically want to just use D Lydian and C Lydian, however, this can get confusing – especially when the chords are whizzing by so quickly. I find an easy way to get through changes like this is to relate everything back to the one primary root note – E in this case. D Lydian will become E Mixolydian and C Lydian will become E Aeolian. As illustrated in Exercise 3, this will be as follows:

Lining up the scales like this makes it much easier to see what’s going on. From E Phygian Dominant to E Mixolydian (D Lydian) the F and the C move up a half step to F# and C#. Then from E Mixolydian (D Lydian) to E Aeolian (C Lydian), the G# and C# move down a half step to G and C. So while it may seem complicated, we are really just changing two notes for each different tonality.

Hear Exercise 3


In conjunction with Exercise 2, here are fingerings for E Mixolydian/D Lydian and E Aeolian/C Lydian in the same three note per string format at the tenth position. By using the same position to play these three different scales it will allow for a much smoother transition when changing between them. Also, if you pinpoint the pertinent notes (the ones that change), it will really help to bring out the different tonalities.

Hear Exercise 4

Use the backing track from Exercise 1 if you’d like to give this a try yourself (or alternatively use Vai’s official backing track). If you’re interested, I’ve also uploaded a clip to my YouTube channel ( of myself improvising over the track: