Learning to adapt to the limitations of your instrument is important. When playing Turkey in the Straw in the key G and in second position there are some melody notes that are lower than the lowest note on the banjo. That's okay! You can make it work for this position and still bring out important melody notes, that way everyone will know the tune you are jamming out to. Check out the licks for this one to really add variety to your version of this tune.
