Interesting comments and both have excellent points regarding the
tune.  Here is yet another factor that was not shared which I noticed
immediately.  There was a change in the pitch at which the selections
are being performed.  When you change keys, depending on whether you
are making it lower or higher, you will have a big factor on how a song
can sound.  The tendency when you place the pitch higher it will make
the selection sound brighter and this is the big difference I noticed
comparing the two.  As to the tempo, yep, that too has a big factor in
how a selection will come across.

Noel Burndahl