[LSR v2.18] "Normalized \transposition" does not compile

[Pierre Perol-Schneider]

Dear Squad,

The following snippet :
http://lsr.dsi.unimi.it/LSR/Item?id=697
Does not compile after a v.218 nor v2.16 upgrade.
Originally made by Jay Anderson (see.
http://lists.gnu.org/archive/html/lilypond-user/2008-06/msg00426.html)
Last try for updating by Kieren MacMillan (see.
http://lists.gnu.org/archive/html/lilypond-user/2013-01/msg00749.html)

Terminal says :
.../all/normalized--transposition.ly'
.../all/normalized--transposition.ly:22:40: In procedure car in expression
(car (ly:music-property key #)):
.../all/normalized--transposition.ly:22:40: Wrong type (expecting pair): ()

Cheers,
Pierre