Mozart K.494: How do you play this (turn inside a tie)?

Question

Mozart K.494 b.178 near the end of the movement. (This is the 3rd movement of the sonata K.533/K.494)

This is in bass clef BTW. This image is the Bärenreiter edition. Henle puts only the turn option.

This looks like a turn while the note is tied — how do you play this? If I try "D4 C4 B♭3 C4" — doesn't that interrupt the tie? Do you actually sound the C4 at the start of the next bar?

This play-with-score version on YouTube doesn't have the turn at this part 25:24 (older edition perhaps?)

Link to timestamp:

Adding a picture of the 2nd turn as answer below suggests a B natural for the first turn:

Answer 1

Playing the turn

Your instinct is correct. The turn would be played C-D-C-B-C (B natural) as a triplet with the final left-hand eighth note, ending on the tied C in the following measure.

This is also true of the turn six bars later, except that it would start on D: D-C-B-C.

It's unexpected that the turn symbols don't include a natural sign underneath. However, it's aesthetically obvious in the sense that since the C is the note being ornamented/emphasized, the B (the leading tone in this context) does the job with more intensity that the Bb.

Recorded evidence

In his recording of the original Rondo in F, Perahia can be heard playing the turns this way.

Shiff and Uchida agree.

Contrary evidence

However, in their recordings of the Sonata, both Gilels and Goode omit the turns, as does Brendel in the F major Rondo.

Answer 2

A tie simply means that multiple notes are combined into a single note. A turn on the other hand is an ornament, and thus something like a way to play a single note. If the note is longer the turn can be delayed, or even (as in this case) in fact become a transition into the next note. In fact, you can use tied notes to actually pinpoint the location where such an ornament should be executed.

So no, the turn does not interrupt the tie, as the tie does not in fact mean "there may be no interruption between these notes" but it means "treat me as one single note".

In fact in more complex rhythmic notation notes that could be notated as single notes are often notated using ties for clarity. Compare these ways of notating the same figure: