how can root notes help me in improvising music by classical guitar?

Question

besides being the notes that build their scales how can they be useful when i improvise using their scales{plz i need something informative}

Answer 1

I'll try to be informative but it is a complicated subject.

What you are really talking about is the concept called (inaccurately) chord scales. You build a scale based not only on the root of the chord but its quality as well.

For instance, if you are in the key of C, and the chord you are playing is a G7th, then the rule states that you would improvise using a G mixolydian scale -- since it has a flat 7.
Each scale also has certain "avoid" tones -- in the above example, C would be a tone to avoid (there are always exceptions to any rule) because it doesn't fit the chord harmonically.

In general, the scales that go with the different quality chords can be generalized as follows:

Major, Major 6th, Major 7th -- Ionian (Major scale) or Lydian Scale (especially with blues) -- this also depends on whether the chord is a I or a IV

Minor, minor 7th, -- Dorian scale
Minor 7th flat 5: Diminished or octatonic scale, or a blues scale
7th chord (dominant 7th): Mixolydian scale
diminished chords -- diminished (octatonic) scale

Things get complex when we start stacking tones -- 9ths, sharp 11s, 13th. In general, in these cases we look to the underlying basic chord quality.

This is very incomplete. Here are some sites that may help. The third one is sort of a tutorial for guitar players

Note: this works for any type of improvisation, not just jazz!

http://en.wikipedia.org/wiki/Jazz_scales
http://www.apassion4jazz.net/keys.html
http://chopsfactory.com/majscales.html

Answer 2

If you have a piano teacher, ask him/her for help. If not, the best thing you should do is hire one. This kind of thing is hard to acheive on your own, so an expert should help some. If you're not financially ready or even willing to get a teacher, try to find a few piano pieces where the chords are nice and light. Then, play the chords one note at a time, from lowest to highest. Best of luck! :)