One of the many songs I've tried to teach piano students is Happy Birthday, since they know people who have a birthday. Who wouldn't love to hear someone play and sing the song on their special day. What a blessing to have that type of special gift given on their day to celebrate their life.
I recently came across an arrangement by William Gillock, through Willis Publishing, taking the basic melody and creating gorgeous arpeggios and various chords. The song is written in the key of F, however Gillock utilizes various chords that are not part of the key. I must be unusual, yet I really like when composers add chords that are not part of the key signature to get your attention. In fact Willis Publishing states:
"An exquisite never-before-published arrangement of Happy Birthday by “the Schubert of children's composers”: William Gillock. Adapted in 1987, the solo is romantic and lyrical with a hand-crossing pattern. It ends solemnly, but with a little wink! (You'll have to play it to understand.) Key: F Major."
This arrangement is true to its words, as it's filled with a romantic style. The person who is playing and hearing the song can sense and know the love for the person who is having their birthday celebrated. So if you're looking for an intermediate arrangement, please check it out.
Thanks for your support. Blessings.