As far as I am aware, Messiaen never gave metronome markings, so it's hard to say whether it's Messiaen who plays "too slow" or other performers who play "too fast" (besides, there
are other performers who
do play as slowly as he does). My personal feeling is that when Messiaen says something like "
extrêmement lent", it ought to be "as slow as possible without disrupting the musical discourse". Messiaen himself does that superbly, in my opinion. Note also his revised edition of Le Banquet Céleste, where he
doubled all note lengths; I strongly suspect that this was in reaction to performers playing it too fast.
I don't know what to think of Messiaen's endorsement of performers he has given so many of them that there is some sense of inflation (in the monetary sense) about them...
As for Franck, we
do have metronome markings for the
Six Pièces (not on the score's manuscript itself, but still on a document in Franck's handwriting). Of course, there may be many explanations for the present performance to be slower than these markings:
- it may not be Franck at all who's playing,
- metronome markings are only an general indication, to be adapted to every venue (although the Trocadéro would have a less generous acoustics than any church Franck could have played/heard his organ works until that point),
- the recording could have been an impromptu request by Edison, and Franck, not specifically prepared for this performance, could have preferred to play slower than usual to avoid wrong notes,
- etc.
Another point I note is about articulation: there is a clear break before the third beat in bar 22 (between D# and B), but otherwise the playing is as legato as one would expect from the "Lemmens school". This is interesting, since Franck's kinness to that performance school has not been as clear as, say, Widor's.