As a Beginner, I have massive gaps in my education. So far I’ve been able to fill these gaps with Confusion, but even that’s not working very well any more.
I would love to get a short, sweet & simple answer, but I’m afraid it’s more complicated than that.
What is the difference between playing a song in D tuning vs playing a song in the key of D?
If my chord progression is 1-4-5, then playing a song in the key of D would be D-G-A.
If my banjo were tuned to D, would the chord progression be the same if the song was in D?  Sure, why not.
SO if I’m getting this right, the tuning sets the “mood” or “color” of the song, while the key is chosen to suit the singer’s voice.
What would “Reuben’s Train” sound like in G tuning?
 I can ponder your answer & glean less confusion.
 I can ponder your answer & glean less confusion.
 ).  A “normal” banjo is tuning is open G.  Every open string is in the G major chord, so the open notes are both useful in the key of G AND you get all that nice ringing of the open G strings even when you aren’t playing on a particular string.  So if you play a song in the key of G, let’s say Amazing Grace, you have the benefit of being able to play the most of the melody notes without even fretting.  You also have the whole banjo ringing with G B and D notes making a lush sound.  Let’s say you have a singer whole can’t sing the lowest note and wants to raise it one half step, G#.  Now you can play the song in the key of G# without re-tuning.  However none of the open strings will ever be used (you will have to fret every melody note and every chord note), and the banjo won’t ring with all the open strings.  So, it’s hard, but you can play the song in the key of G# tuned to open G.  It’s just very difficult and won’t sound great.  We can capo up to the first fret and that results in us playing in open G# tuning.  Back to easy and sounds great.  What if you don’t have a capo (or spike on the fifth string)?  You could re-tune the entire banjo up a fret and we have now tuned to open G# so that we can easily play in the key of G#.  Again, back to easy and sounds great.  Hopefully that helps.
).  A “normal” banjo is tuning is open G.  Every open string is in the G major chord, so the open notes are both useful in the key of G AND you get all that nice ringing of the open G strings even when you aren’t playing on a particular string.  So if you play a song in the key of G, let’s say Amazing Grace, you have the benefit of being able to play the most of the melody notes without even fretting.  You also have the whole banjo ringing with G B and D notes making a lush sound.  Let’s say you have a singer whole can’t sing the lowest note and wants to raise it one half step, G#.  Now you can play the song in the key of G# without re-tuning.  However none of the open strings will ever be used (you will have to fret every melody note and every chord note), and the banjo won’t ring with all the open strings.  So, it’s hard, but you can play the song in the key of G# tuned to open G.  It’s just very difficult and won’t sound great.  We can capo up to the first fret and that results in us playing in open G# tuning.  Back to easy and sounds great.  What if you don’t have a capo (or spike on the fifth string)?  You could re-tune the entire banjo up a fret and we have now tuned to open G# so that we can easily play in the key of G#.  Again, back to easy and sounds great.  Hopefully that helps.


