Chord Shapes choice -open or barre chords

So slowly learning both electric and acoustic guitar & getting a little confused about playing open chords and barre chords.

For example you can play the G chord with 4 fingers, 3 fingers and 2 fingers. The C open chord can be 3 or even 4 fingers or they substitute the C for Cadd 9.  I have watched plenty of clips and lessons when guitarists alternate the chord shapes depending on the song or even using different fingers and shapes  in the one song. This applies to changing from open to barre chords. For example some will play the open G whilst others play the same song with the Barre G.

So when do you choose what chord shapes to use in a song or doesn't it matter?  Hopefully I have explained this clearly.

Any help appreciated.

This is where it’s important to listen carefully to what is being played and then try to find that same chord on the guitar. The chord finder here is very handy for that. 

When I am roughing in a song by ear, I recognize the chords by playing the notes. That gives me a quick and dirty way to write down my chord changes. Example would be A and this is a recent example of what happened.

 I knew the song changed to an A chord, because the A note fit over that section, but A major didn’t work, A minor didn’t work, nor did a power chord.

I opened the chord finder and started trying different A chords over that section of the song and it turned out to be an Asus4. I had never heard of it before, but now I can play it.

So some leg work was involved but I did get it.

Hope that helps.

This is a good question.  Thanks to William for the great reply with practical advice.  I'll add some ideas to help clarify.

In general the answer is that you choose the chord voicing that has the sound you want for the music you are making.  But the answer also depends on your skill level & musical goals.

When you are a beginner, mostly the answer is no, it doesn't matter.  Play any version of the right chord at the right time to get through the song & that's good enough!

When you start wanting to improve your musicianship & get deeper into a specific genre of music, then it starts to matter more.  That's why we have different style courses.  Each style of music uses more specific chord voicings in very specific ways in order to get the right sound. 

https://www.guitartricks.com/experienced

Many times you'll see that you don't use either open chords or the full barre chords, but instead just partial voicings of each.   And each style has it's own way of playing any chord with extensions or embellishments that give that particular style it's characteristic sound.

For example, a blues song might only use low register boogie diads, or upper register shell voicings.  A rock song might just use power chords, or 3 note triads which are a small part of a barre chord.  Often you'll find that songs with more than one guitar part have different voicings of the same chords used at the same time so the guitar parts compliment each other & don't get in each others way.

As you learn more & refine your playing you discover more ways to play chords in order to get different sounds.   

This tutorial covers the basic concept of chord theory, just to give you an idea of what is possible.  

https://www.guitartricks.com/tutorial/148

Hope that helps!

Thanks William and Chris really appreciate the response. Being a long time Dylan fan this helps me understand his style a bit better as well.

Thanks again

You're welcome!