Today we had our first full run through of the song as a band, at first we ran into a few issues regarding timing - mostly in the choruses. However, we were able to work past the problems after playing in smaller groups. For example, I would play only with Emily (Who was singing), work out where the chord change should be and where I was playing it, and if it was wrong - which it was - correct it, with reference to the original piece. I found this to be a fantastic way to overcome the problem as Emily was the most helpful person to work with in regard to timing as she is the vocalist. We played the piece through fully twice, and on the second run through I didn't hear anything that needed improving, although I believe the transition between Verses 3 and 4 could do with some work. To work on this the group could timetable some rehearsal sessions outside of class, even if the sessions were only brief.
During the intro to the piece, where only one guitar, one piano and vocals are playing, I found that again timing could be worked on. Myles, who is playing the piano during the intro, came up with a great method to help keep timing between the guitar and piano by subtly and quietly playing the chord 4 times, to the count of 4 beats so that we both knew when to progress chords. I will need to practice at home along with the original piece, one rehearsal every other night would probably be the most efficient schedule. If I stick to this, I should have no problems with timing when the recording date rolls around.
Below is a clip of a band called Royal Pirates performing All I Want For Christmas Is You in rock style, similar to how our rendition is played.
The chords were quite challenging at first, although strangely I found that the pattern is similar to Eddie Cochran's Summertime Blues, which helped a lot as I have played that a lot in the past making chord changes, and some of the strange chord shapes (B7) easier to deal with. The chords used in the piece are: G, C, Cm, B7, Em, E7, Am7, Am7/D & D. Some of these chords were (and still are slightly) difficult to play, mostly the last chords. Their positions are pictured below:
A B7 Chord:

An Am7/D Chord: