https://www.deeringbanjos.com/blogs/banjo-maintenance-tips/9210375-how-to-tune-a-banjo
How To Tune A Banjo
5-String Banjo
G, D, G, B, D
The most standard 5-string banjo tuning. This is referred to as “Open G” Tuning because the banjo is tuned to an open G chord, meaning that if you strum the banjo without fingering any of the strings on the neck you will be playing a G chord.
G, C, G, C, D
Often used in Old Time music, this is referred to as “Double C” Tuning because the banjo has two C strings. A capo is often put on at the second fret to bring the banjo into “Double D” tuning.
Learn How To Tune a Banjo To Double C Tuning Using Your Ear!
G, C, G, B, D
This is referred to as “C” Tuning. It can also be referred to as “Drop C” Tuning because coming from the open G tuning, the D string on the 4th string is dropped down to a C.
F#, D, F#, A, D
This is referred to as “D” Tuning. Earl Scruggs used this tuning on such songs as “Reuben”. You can also tune the 5th string to an “A” instead of a “F#” and still be in “D” tuning. If you strum the banjo without fretting any strings in this tuning you will be playing a D chord.
G, D, G, C, D
This is referred to as “G Modal” Tuning. This is a very popular tuning for old time tunes such as Shady Grove, Little Sadie, and many others. It is also sometimes called “Sawmill Tuning” or “Mountain Minor Tuning.” This is very close to standard G tuning but the second string is tuned up to a C note. This eliminates the third of the G chord and produces a G sus 4 chord. By eliminating the third of the chord, you cannot tell if it is a major or minor chord and gives it a modal sound.