The APP CD liner notes credit John Evan with 'speech'. Since the only substantial spoken section of the album is 'The Hare...', many people have understandably presumed that the narrator's voice is John's.
But it's not.
My best guess is that 'speech' refers to the spoken interjections in the main Play, such as 'And your little sister's immaculate virginity...'. There are very few instances on the finished album, so few as to hardly require a proper credit. However, in the Chateau version, there were several more such instances, which might justify a mention. So I'm suggesting that the album credit is more for his work in the aborted sessions than used on the finished album.
Also, as Michael Dawson points out: Jeffrey is credited with vocals on the album; there is no point in giving him a separate credit for speech. John speaks but has no singing part, so he gets the more specific credit.
It's interesting that Tull's 1973 concerts featured 'No Rehearsal' in addition to the entire Play. This suggests that the band, or at least Ian, was particularly attached to the song, despite it not fitting the theme of The Play well enough to have gone on the album itself - or it just didn't fit onto the LP!
On the whole, the tracks presented on Nightcap seem to be additional to those on 'A Passion Play' - these are the tracks that were dumped outright, rather than being reworked for inclusion on the final album. Three exceptions are 'Tiger Toon', 'Critique Oblique' and 'Post Last'.
'Tiger Toon' forms the core of The Play's 'Prelude'.
In terms of the lyrics, 'Critique Oblique' is very close to the version on APP. However, the Chateau version is clearly unfinished, lacking most of its lyrics, which might have been totally different if completed. It's also clear that the Chateau version was to have been rather more substantial, and presumably feature more lyrics than its APP equivalent - whilst the APP track has a running time of 4 minutes and 38 seconds, the Chateau version is two seconds over nine minutes long.
'Post Last', lacking virtually all of its lyrics on 'Nightcap' seems to have been incorporated into APP virtually in its entirety, becoming both 'Best Friends' and 'Critique Oblique'. This is a key point - on Nightcap, the 5½-minute 'Post Last' follows the 9-minute 'Critique Oblique', whereas on APP, both are abbreviated and condensed into 6½ minutes on APP.
It has to be remembered that the APP version of 'Critique Oblique' is a working draft of the Chateau piece, rather than their being two fully realised and complementary parts of the same song. It has been suggested that combining the lyrics of each creates 'the full song', but there's no logical reason to believe that was the original intent; 'A' (Chateau) plus 'B' (APP) doesn't equal 'C' (full song), 'A' plus 'x' (reworking) equals 'B'.
It has been suggested that there's a progression of the theatrical metaphor from "Critic of the black and white..." in the Chateau version, to "Actor of the low high-Q..." in the APP version, to an unspoken third: either God the director from 'Scenario' or the playwright/author (which has to be omitted, as Ian can't talk to himself!). A tempting idea, if it wasn't an absurdly selective use of partial facts.
"Critic of the black and white..." was a working version, which was dumped in favour of "Lover of the black and white..." in The Play. The rest of that stanza is identical in both versions, so it's plain that one replaced the other - they're not two verses of the same song.
The theory conveniently ignores the lines that don't support it, a fact that simply invalidates the whole idea. I see no progression whatsoever from "Lover of the black and white..." (not 'critic', as that has been discounted already) to "Actor of the low high-Q..." to "Man of passion rise again,...".
It might - might - be reasonable to assume that the track order on Nightcap was chosen to reflect their intended sequencing on the aborted album. However, that still leaves complete uncertainty about additional tracks - does 'Post Last' really lead straight into 'Scenario', or might there have been another linking piece between them?
One such fragment is known to fans as 'Sailor'; a name ascribed by Sam Thirouin as being as good as any, though it's doubtful that Ian even gave it a name:
When the holy film director decides to take a look,
refers to the pages of his holy book,
sends the warm rain falling from the sky,
if you've never been a sailor better try
if you've never been a sailor you better try...
(repeated, to a total track length of 1½ min)
In the 'raw' Chateau tapes, this track lies between 'Skating Away...' and the beginning of 'No Rehearsal'. However, this might only reflect the order in which the sessions progressed, not necessarily the intended running order of the album. It's quite likely Ian recorded a brief idea as soon as he thought of it, to be fleshed-out and properly sequenced later.