Originally Posted by: axe2Ok im getting frustrated ,about the A Dorian scale mod.

Modes & scale practice can get frustrating! Exactly what are you frustrated about? Just that there are different possible patterns?

Remember that since you can play the same exact note in more than one place on the guitar there are almost always going to be more than one way to play any given scale.

Further, if you are starting any type of three string per note pattern on the root note, then there are at least three different positions you can use.

1. Index finger in lowest position on the root.
2. Middle or ring finger in middle position on the root.
3. Pinky finger in highest position on the root..

I cover this in depth in these tutorials on major & minor scale patterns.

http://www.guitartricks.com/tutorial.php?input=453
http://www.guitartricks.com/tutorial.php?input=887

For example, A dorian can be played like this.

E ||---|---|---|---|---|---|---|---|---|---|
B ||---|---|---|---|---|---|-6-|-7-|---|-1-|
G ||---|---|---|---|-3-|---|-4-|---|-5-|---|
D ||---|---|---|---|-7-|---|-1-|---|-2-|---|
A ||---|---|---|---|-4-|---|-5-|---|-6-|---|
E ||---|---|---|---|-1-|---|-2-|-3-|---|---|

Or like this.

E ||---|---|---|---|-1-|---|---|---|---|---|
B ||---|---|---|---|-5-|---|-6-|-7-|---|---|
G ||---|---|---|-2-|-3-|---|-4-|---|---|---|
D ||---|---|---|-6-|-7-|---|-1-|---|---|---|
A ||---|---|-3-|---|-4-|---|-5-|---|---|---|
E ||---|---|---|---|-1-|---|-2-|---|---|---|

Or like this.

E ||---|---|-7-|---|-1-|---|---|---|---|---|
B ||---|---|-4-|---|-5-|---|-6-|---|---|---|
G ||---|-1-|---|-2-|-3-|---|---|---|---|---|
D ||---|-5-|---|-6-|-7-|---|---|---|---|---|
A ||---|-2-|-3-|---|-4-|---|---|---|---|---|
E ||---|---|---|---|-1-|---|---|---|---|---|

These all contain the same notes. Ultimately, you should be aware of this & practice all of them. Each one has its own pros & cons depending upon what you need to do with them when you are playing music. Some patterns are easier for some groups of notes & some for others. Each one sounds a little different because certain notes are played on wound strings versus unwound, because the string length is longer versus shorter resulting in a slightly different timbre.

For example, let's look at this Dorian lick.

|--8-7-5-------------------------------------|
|---------8-7-5------------------------------|
|----------------7-5-4-----------------------|
|-----------------------7-5-4----------------|
|------------------------------7-------------|
|--------------------------------------------|

There's a lot of similar shaped patterns (symmetry!) in the E & B strings, then the G & D strings making it easier to play those notes.

But, if you played those same exact notes like this, it might be a little more tricky & inconvenient.

|--8-7-5-------------------------------------|
|---------8-7-5------------------------------|
|----------------7-5-------------------------|
|---------------------9-7-5------------------|
|----------------------------9-7-------------|
|--------------------------------------------|

You'll notice there is a different sound to playing the B note on the unwound G string versus the wound D string. So, there is a slightly different timbre or tone. But it is the same exact note in both places. Same for the F#, it might sound a little more bassy because playing it on the A string instead of the D string puts it on a thicker string & gives it a little less string to ring on.

You might choose the first pattern because it's easier to play & it sounds right for the piece of music you are currently playing. You might choose the second pattern because it works better for the sound you are after in a different piece of music!

Hope this helps!