Climber:
Your question: What mode is used in the 7th bar of the solo on Time Machine?
A: The “booming” orchestral notes behind that magnificent solo are D and Ab - so I’m pretty sure the solo is D Lydian (the Ab wouldn’t really work unless you phrased, or Joe was using, Lydian). I don’t have a guitar with me now and never actually learned that solo, I just listened to it a lot (hint). It’s the flat 5 (Ab) that really sticks out for me and when you use it (flat 5 or sharp 4) more often the sound will become instantly recognizable. The next part sounds like C Mixolydian – the key tone is the Bb. The D Lydian section is 16 bars.
I always recommend learning modes as they relate to a major scale. In other words concentrate on what notes are altered to give it its sound – in this case the 5 is flatted or the 4 is #. I don’t recommend the approach of saying that D Lydian is actually an A major scale starting and stopping on the 4th note. Your better off looking at it simply as a major scale with a sharp 4th.
Lydian formula = 1, 2, 3, #4, 5, 6, 7, 1
Ludian is notated as #4 because if you list the formula with a b5 you may actually play the 4 with it creating 1,2,3,4,b5,5,6,7 or flat the 5 and omit the natural 5th which is kinda needed with this scale - IMHO the formula above is the best way to "look at it". More importantly - listen for that #4. Some good chord choices are a Major 7th -since the Major 7th is 1,3,5,7 the raised fourth works well and actually sounds as good as the natural 4 or suspended 4th. Obviously Lydian is diatonic when used over the IV chord (major) and is usually always the scale for a maj7#11 chord.
In Time Machine the power move from D to a lower Ab provides a perfect context to just lay into a Lydian free for all. Mr. Satriani uses this scale, Phrygian and just about all the rest of the modes perfectly.
I'm listening to it again and pretty sure this is right - someone let me know if my ear is on break.
If Joe Satriani ever reads this, don’t kill me for very well having over explained this. Climber asked for the time and I built him a time machine – LOL
Rock On