As short and simple as this song is, it has a lot going on! First of all, it's a good tune for beginning guitars as it only has three chords, all of which have easy, four-string options.
Second, this tune has a part for bells and/or Boomwhackers®. Really, it could be used for any C instrument, like xylos, recorders, tone chimes.
Finally, it's very easy to sing, so you could let students sing while they play guitar, if you wish. And the song is about friendship, making it perfect for Valentine's Day or any time. (from Music K-8, Vol. 22, No. 3)