look at the title, do you thing which is the most important when writing a solo?
the fact is I never use pentatonic scale... but i can pick fast on major scale (16th at 120 bpm at this time, actually more)...

I just wondering, is people that have a concert or gigs always using pentatonic to solo, or improvising... they seems not play in one area (example: area fret 5 to 9, ascending or descending)

I've been played since july last year... and i have a lot of passion in playing guitar... I want to shred like vai, so what scale recommended? or can help me pick any good scale other than stated above, please...

Actually i am impressed to whom can shred although they're below my age...
I am not taking any class...
If you want to play like Steve Vai, you want to learn as many different kinds of scales as possible, such as: The major scale and all of its modes, altered scales/modes, melodic and harmonic minor and all of their modes, both types of diminished, whole tone scale, and various oriental scales.

When you get those down, learn to modulate. In other words, look at what chord is being played and pick what scale best fits it according to what notes are being played. For example:

A G7 chord is played, which has the notes: g, b, d, and f. Those are the 1, 3, 5, and b7 of the G major scale. A mode of G that has those same notes is G mixolydian: 1, 2, 3, 4, 5, 6, b7 (g, a, b, c, d, e, f) as aposed to G major (or ionian), which has the notes g, a, b, c, d, e, f# (1, 2, 3, 4, 5, 6, 7).

I also recommend reading this lesson: http://www.ultimate-guitar.com/lessons/music_styles/jazz_lessons_part_1_-_the_beginning.html

The reason for this is because jazz focuses on atmosphere, phrasing, and complex harmonies rather than then pure technique, and so does Steve Vai.

As for shredding, I can't help you...
Carpe diem; Seize the day.

Just be.

Scales are notes, not shapes, boxes, or patterns.
Last edited by fendermalmsteen at Sep 3, 2006,
Lydian, lol. Learn lydian if you want to sound somewhat like Steve Vai.

And no scale is more important than the next... they all have their place and are all important depending on where you're using them.. personally if I'm in a pentatonic scale, I'll add flavour notes... add the 2nd in the major pentatonic, or the b5 in the minor pentatonic.. mixing and fusing both pentatonic and diatonic together. Sticking strictly pentatonic will get boring, which is why you'll see a lot of people adding in some extra notes for flavour.