There are two pieces :
- the Offertoire in g minor at
0:00 (it was later renamed "Pièce symphonique" when edited by Tournemire, a bit emphatically but not without some reasons) ;
- the Allegretto in D at
7:30.
Those pieces are somewhat "Franck before Franck". More precisely, they were written around 1855-59, roughly ten years before the Six Pieces. They show a Franck still composing in typical Second Empire period style, like did Batiste or Lefébure-Wély :
- the offertoire is somewhat parent of Lefébure's one in d minor, even if more serious (
http://www.contrebombarde.com/concerthall/music/21650 by Aarnoud) ;
- the Allegretto is tiny small brother of another well-known Lefébure
(
http://www.contrebombarde.com/concerthall/music/8900 by Milan).
Nevertheless, we can find in the Offertoire many characteristic features of Franck's later compositions :
- an abundant thematic material, as in fantaisie in A : 4 themes ;
- typical Franck's melodic tricks ( see
2:04 and
2:50) he used very often ;
- a kind of a "loose and shortly ending fugato" in the middle of the piece (
3:22), as in Pastorale , Grande pièce symphonique or 2nd Choral ;
- superposition of the two main themes in the last part (see
4:09 and
5:22), as in Fantaisie in A or Pastorale or 2nd and 3rd Choral ;
- around
4:15 , it's quite similar to some bars in the middle part of the Finale ;
- the general atmosphere has something of the PIèce héroïque.
The offertoire provides also an opportunity to use the typically French "pédale d'orage" at
4:41.
This music was obscured by the shadow of Six pieces, Three pieces and Three chorals. It is today largely forgotten and neglected. Sure the Offertoire is a sometimes emphatic and the Allegretto doesn't lack saccharine, but these pieces are IMHO highly enjoyable to learn and to play ; enjoyable to listen to ? it's your opinion which matters :-)
PS : they were edited by Tournemire in L'Organiste vol.2. But they are organ pieces, not harmonium