After I was all done with this arrangement and video, I wondered what the hymn would sound like in the key of C. Turns out, it is even easier than in the key of D. Therefore, if you are so inclined and wish to make a longer solo guitar arrangement, it would be a good exercise for you to work it up in C so that you begin in C and modulate to D for a second verse. You can even toggle back and forth between the keys, which is often how I do Joyful, Joyful, We Adore Thee (switching between the keys of G and C) at the end of Mass as a postlude until the church has nearly emptied out.