when I am improvising lead licks along with songs I have a hard time selecting the right scale to fit the song in a melodic sense, even if I now the key. For example I have been playing against a G, D, Emin, C progression (key of G major) and have been using a G major scale but for what ever reason it doesn't sound that good. Basically I am looking for advice on which scale (major scale, minor scale, major penatonic, or minor penatonic) I should use and when.
You could use G Mixolydian, so long as you don't play the F over the D chord too much.
Use the G major pentatonic as well. And until you learn why what I'm about to say is the same as G major, you can use the Em scale and Em pentatonic as well (I can explain why this isn't really right later, but for now it works).

G major is the appropriate scale, so it's a phrasing issue that you will resolve with practice. The "Melodic Control-Learn to Solo" link in my sig deals with phrasing if you're interested.

However, this would not be a scenario where you would likely use the Gm pentatonic over a major progression as it is pure major and not bluesy.
when i strum those chords...it sounds like, when i come around.

I guess it would be I, V,VI,IV movement

The easiest way to do it is to use the corrosponding mode over
the each chord.

play around the arppgeios of each chords.

You can use maj pentatonic over all of the maj chords,
or min pentatonic over the minor chord.

meaning play Dmaj pentan over D, C major penta over C...etc.

Don't worry you won't hit a sour note becuase within the pentatonic
scale are the arppegios of each chords

Then just fill in the two notes of each mode if you wanna give it
a more complete sound of a mode.
Last edited by Ordinary at May 13, 2008,
Lots of chord tones. Playing a m6 over a minor chord(C over that E minor) or things like that don't always sound good.