Midi tuning on Kunst Der Fugue site

This is one of the main classical midi sites, and it has some
tuning-related stuff in an incidental way. For Scarlatti, it has some
very nice midi performances of all 555 sonatas, in zipped format.
About the tuning of this, the performer/sequencer, John Sankey, has
this to say:

A twelve-note scale can not have all intervals in tune at the

same time. MIDI systems default to equal tempering, where only

octaves are really in tune. This tuning was not musically

acceptable to keyboard musicians of Scarlatti's time, who

restricted the keys they played in so that more of the

musically-important intervals could be in tune. They also

valued the variety of characters that differing keys have when

all intervals are not equal. I used a technique of consonance

analysis (W.A.Sethares, Journal of the Acoustical Society of

America 96:10, 1994) to aid me in finding the systems of

tuning that Scarlatti probably used most commonly, since no

records of it survive other than the music itself. These

recordings use the best tuning I have found, one published by

d'Alembert in 1752 and refined for these sonatas by the

consonance technique.

On the Pachelbel Magnificat page,

http://www.kunstderfuge.com/pachelbelmagnificat.htm

we find tunings in various temperaments, and an explanation of how to
use Scala to do it.