A brief tuning example from the Master, “Ave verum corpus”, K 618. Is my interpretation right? I don’t know …
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.
Further update: new post on third phrase: http://intonalist.wordpress.com/2014/01/31/mozart-ave-verum-example-3/