trills (haydn)

[Tash]

i have to write and perform a thing on historical performance practice on a classical or romantic piece so i'm most likely playing the 1st movement of haydn's Eb sonata (no.62), except in this one little section https://i2.tinypic.com/qo6pmg.jpg i am wondering if there's some wonderful explanation as to why the trills don't start on the upper note- is it just because they're quick and it'd sound weird if you did? have skimmed c.p.e bach's essay on keyboard playing except if he mentioned something on it i missed it...thanks!!

[pianistimo]

i'm guessing here, but  looking at the speed of the passage (16th notes) you might not have time to do a full trill while playing a descending scale.  the triplet trill does sound right and is often done (even in slow passages) in certain places in mozart.  esp. if the preceding upper note is one note higher than the trilled note.  otherwise, you have to play the same note twice. 

 

[galonia]

You should start on the note, and not the note above, because that way you preserve the melodic line.  It sounds bizarre (and a bit like you have the hiccups) if you start on the note above.  Try it.