I use this mainly as a reading/decoding exercise with my first graders.  There are endless extension activities that you can do with this from adding instruments, vocal exploration warm-ups, part work using body percussion with beat vs. rhythm, etc..  In fact, Liza Meyers blogged about it a couple years ago and has a fabulous post where you can read some of her ideas by clicking here.

Now, back to the decoding activity that I do.  My students read the the chant from a poster that I made "back in the day" (you know, before these new fangled contraptions called LCD-Projectors, SMART boards and document cameras, lol!).  Here it is:

 It's not high-tech but it gets the job done and the kids like the silly pictures.  After they know the chant (not in the same lesson that they learn the chant), I have them listen for a specific rhythmic pattern.  For example, I'll ask them if they hear the pattern ti-ti ta ti-ti ta.  They decode that it's the ghost line.  Then they read the chant, substituting the rhythm syllables for the decoded line WHILE listening for another rhythm pattern.  This continues until they have aurally decoded the entire chant and perform the chant on rhythm syllables only.

On another day, we will do a notational decoding.  I have the rhythm patterns from the song (see below) printed out and cut into strips of paper so that there is only one phrase per strip of paper.  Working in alone or in pairs (depending on your stage of practice or students' level of reading ability), they receive and envelope that contains all four rhythmic patterns.  They then put the rhythm patterns in order to match the song.  A fun extension activity is to have them arrange the strips however they like and perform them in that order.  If you have students who need and extra challenge (you know, those kiddos that have been in piano a couple years or really pick up on things quickly) you can have them perform their rhythmic pattern while the rest of the group performs the "Miss White" chant.