Re: tie over clef change

[Hans Åberg]

> On 26 Sep 2020, at 20:58, Kevin Barry <barrykp@gmail.com> wrote:
> 
> On Sat, 26 Sep 2020 at 19:30, Hans Åberg <haberg-1@telia.com> wrote:
>>>>>> The notes d♯ to e♭ have different pitches in the staff notation
>>>>>> system, which cannot express E12 enharmonic equivalents, so this
>>>>>> is slur. So it should be a slur that looks like slur.
>>> 
>>> I disagree.  For all practical purposes in standard classical music,
>>> enharmonic equivalents *do* sound the same.  What you are referring to
>>> IMHO is a special case that might be controlled by a flag.
>> 
>> They do not, and the string section, that primarily stands for the pitch
>> reference, trains to slide the pitch appropriately:
> 
> In some contexts a notated D sharp and E flat are the same pitch (e.g.
> equally tempered piano music) and in some they are not (as you pointed
> out). Since this is a discussion about ties, where the note is the
> same by definition, we can assume we are dealing with the same pitch.

The staff notation pitches are different in the case of an enharmonic tie, as 
in Dan's example d♯ to e♭. You might want to have a tie here to make the 
enharmonic change explicit. —That is perhaps what you meant, but I find it 
confusing saying that d♯ to e♭ are the same pitch, because in the case of staff 
notation, they are not, even though in some music, they can be played the same.

> The question isn't whether it's a tie or a slur, but how LilyPond
> should render a tie when the two notes are not aligned (i.e. the user
> has entered a "~" indicating that it's a tie).

Say the ties are rendered as usual, but the slurs are dotted lines, and the 
phrase marks are square brackets. How do you want the output to be then?

> I agree with Gould that ties across clef changes should be avoided (I
> personally wouldn't even do it in the Liszt example posted), but I
> think LilyPond needs to handle it. I think it's quite acceptable to
> detect this situation and switch to using a slur (but I haven't looked
> at the code).

So if one makes them radically different, substituting ties and slurs for each 
other in the output would not work.