A brief tuning example from the Master, “Ave verum corpus”, K 618. Is my interpretation right? I don’t know …
[update] I have not improved these early recordings, see the last post in April 2014 for the final recording.
[update] lower in the post are pdfs with more of the Mozart Ave Verum Corpus, and here the final phrase.
PDF example: k618_aveverum_ex1
Note the alto and tenor, bar 2! The “eh” syllable has been said to lead to flatness, so Mozart uses that effectively.
At the bottom of the pdf page here are the symbols for intonation.
Update in response to comment: the tuning symbols indicate my prescription, right or wrong, for how it should be sung and played. What to do with the organ, given in the score I looked at from Neue Mozart Ausgabe, only as a bass line, doubling the ‘celli and basses, I don’t know. But crudely doubling the upper strings doesn’t seem right, nor does ‘figuring’ independently .. is your organist’s improvisation better than Mozart? So I’d say the organ is there solely because of union rules.
As to the second measure, I believe the second half has to be taken as an independent chord, ii 4-3 ( third inversion of a ii7), and the pitches thus are those from the subdominant side of things. And the first half, then, a V 4-3 of V, with the raised intonation, the dominant side, that that requires in the tenor and alto.
Further update: another phrase. and pdf example : k618_aveverum_ex2
Further update: new post on third phrase: https://intonalist.wordpress.com/2014/01/31/mozart-ave-verum-example-3/
William Copper
intonalist 
Well, I’m not able to answer your question of whether your interpretation is right, but I have a question or two to ask so that I might better understand what’s going on here, if that’s ok.
Are the symbols in the pdf file an analysis of how you think this should be performed or how the pitches would respond in a ‘pure’ intonation to one another? (not sure that’s a good way to phrase that) Or both?
You’ve brought up the second measure, so maybe that’s a good place to start. Here’s my thoughts. The first notes of the second measure are all related to each other by a fifth, correct? That might be why you have indicated the SAT as pure dominants above the tonic that’s in the bass voice? The alto and tenor go flat in the second half of the measure as a response to the G natural (sub-dominant) in the soprano? Thinking maybe the chromatic G# is a brief V of V, or an anticipation.
I’m curious to know more about what’s going on in this example.
Yes to the first question: the symbols are a prescription for how I believe it should be sung.
As to the second measure, I believe the second half has to be taken as an independent chord, ii 4-3 ( third inversion of a ii7), and the pitches thus are those from the subdominant side of things. And the first half, then, a V 4-3 of V, with the raised intonation, the dominant side, that that requires in the tenor and alto.
The soprano A in the second measure is a suspension, regardless.
I’ll edit the original post and put some of this there, too … thanks for making me look at it yet more carefully. And, disclaimer: it’s quite possible I’m wrong about everything.
Agree with the ii7. That inversion is commonly seen in Bach as well; blurs the line between resembling a ii or a IV. I hadn’t thought much about this in terms of intonation considerations, but seems probable in using one analysis over another.
And the suspension.
Also, I’m quite possibly wrong about everything as well; can’t always be right.
Thanks for the observation. I hadn’t realized you had a blog on music too, will reference it in my earlier posts about other thoughtful blogs.
William