[pchuckie]

Beginner here and I have several books I've been reading on how to read music. The one question that none of my books have answered, or presented the information to me so I could comprehend it is. Lets take the A note, it can be played in 6 places prior to the 12th fret and in six more places on the other side of the 12 fret. I think I got that part right. Now when you see the 6 bar music notation and it shows to play an A note how do you know what string to play the A note on and which side of the 12 fret. I pic right handed if that helps someones explanation.

[Dolenz]

I'm sure others can explain it better and have better guidelines but remember that the A notes you are talking about that you can play prior to the 12th fret are actually three different A notes. Low A appears two ledger lines below the standard notation lines. Middle A appears in the second space between lines and high A is one ledger line above the standard notation lines.

So right there you have narrowed your possibilities beneath the 12th fret to 2 possibilities for each version of the A note (low, middle, high)

Is there a trick to knowing which one to use? If there is I don't know it because I am still a relative beginner. I would think the deciding factor would be the song itself and where it is taking you. If the song takes you mostly into the higher registers I would probably choose the A note on the higher numbered fret - songs mostly in the lower register I would look to stay near the lower frets. Beyond that I don't think there is a wrong or right answer.

I hope that made sense and that I did not embarrass myself with my first post. If I am completely off base I am sure those more knowledgeable then I will follow with a better answer.

[Fretsource]

As Dolenz said, some of those 'A' notes are different (low , middle and high - and even one which is very high). Which A are you asking about? I guess, if you are a beginner, it's the one on the 2nd space of the staff - (the one above the G line that the treble clef curls around).
That particular A can be found in four places on the guitar. It can be played on string 3 fret 2, string 4 fret 7, string 5 fret 12 and string 6 fret 17.

But as a beginner, you can forget about ALL of them except the first one - string 3 fret 2. A beginner's book on reading music for guitar will introduce that one on string 3 long before you ever get to learn about its alternative location on string 4 or elsewhere.

The other two As that you will learn as a beginner are the high A on string 1 fret 5 and the low A on the fifth open string. Those also have alternative locations, but it will be ages before you ever have to worry about those.

When you're more advanced, a lot of the time, it will be up to you to decide which is the best place (i.e., most sensible place) to play any particular note. As Dolenz also wisely points out, it depends what your other fingers are doing at the time. If you are already up near the twelfth fret, it would be easier to find a middle A up there somewhere than come charging all the way down to the second fret just for one note.

If the songwriter, composer or arranger wants a note played in a particular place they will show that by placing the string number inside a circle, placed next to the note, or by telling you which fret position to place your hand (they use Roman numerals for that) - otherwise it's up to you. Just don't confuse a low A with a middle A or a high A

[pchuckie]

Thanks fellas