Re: [tablatures] transposing tablature

[Carl Sorensen <c_sorensen@xxxxxxx>]

On 1/9/10 12:17 PM, "Patrick Schmidt" <p.l.schmidt@xxxxxx> wrote:

> 
> 
> -------- Original-Nachricht --------
>> Datum: Fri, 8 Jan 2010 20:47:50 -0700
>> Von: Carl Sorensen <c_sorensen@xxxxxxx>
>> An: Carl Sorensen <c_sorensen@xxxxxxx>, Patrick Schmidt <p.l.schmidt@xxxxxxx>,
>> "tablatures@xxxxxxxxxxx" <tablatures@xxxxxxxxxxx>
>> Betreff: Re: [tablatures] transposing tablature
> 
>> 
>> 
>> 
>> On 1/8/10 7:50 PM, "Carl Sorensen" <c_sorensen@xxxxxxx> wrote:
>> 
>>> 
>>> 
>>> 
>>> 
>>> On 1/8/10 12:05 PM, "Patrick Schmidt" <p.l.schmidt@xxxxxx> wrote:
>>> 

>>>> You get an inverted 4-note d major (sixth) chord in first position. The
>> root
>>>> of the former c major chord got lost in transposition by default
>> because the
>>>> root of the resulting d major chord would be on the fifth fret of the
>> fifth
>>>> string. LilyPond tries to find the corresponding pitches in the first
>> four
>>>> frets of the guitar because the default value of minimumFret is zero.
>> In my
>>>> opinion this behaviour is wrong because not all the pitches of the new
>> chord
>>>> can be found in first position.
>>> 
>>> This is a bug.  Minimum fret should not default to zero.  It should
>> default
>>> to unset, and the code should be able to find the correct chord.
>>> 
>>> I had missed this problem before in your code.  I apologize for not
>>> understanding it.
>>> 
> No need to apologize, it was my fault.
>>> I think I can fix this bug.  I'll try to get to it in the next couple of
>>> hours.
> Thanks very much!
>> 
>> Patrick,
>> 
>> Can you add a FretBoards context and do some experimenting to see if the
>> chords transpose properly in the FretBoards context?
> Work in progress
>> 
>> For the particular case you gave, the FretBoards function works properly..
>> 
>> If the FretBoards function works properly to give the tablature you want,
>> I'll adjust the tab-note-head engraver so it uses the same note-to-fret
>> function that the FretBoards engraver uses.
>> 
>> I think this is the proper thing to have happen, anyway.
> Sounds good to me. By the way: Would you mind me adding (quite) a few fret
> diagrams to predefined-fretboards.ly? If yes: is it possible to add several
> diagrams of the same chord e.g. C major: A-shape (III. position), G-shape (V.
> position), E-shape (VIII. position) and D-shape (X. position). I could also
> add lots of inverted chords, eleventh, thirteenth and so on. Why are there two
> separate fretboard files?
> 

I would be fine to have you add diagrams to predefined-guitar-fretboards.ly..

We have two separate guitar fretboard files because we want to show in the
documentation that if a chord is not included in the predefined fretboards,
a chord shape will be automatically calculated.

It is possible to add several diagrams of the same chord by using different
octaves.  However, the octaves should probably be two apart, e.g. c and c'',
but not c'.  Because of this, I would recommend that we *not* have all of
the possible shapes for each of the chords in the default file
ly/predefined-guitar-fretboards.ly.  I think we'd fill up the "octave" name
space.

If you can think of a good classification scheme, perhaps we could put these
chords into separate .ly files, and the user could then include them as
desired.

If you're going to add different chords with the A shape, E shape, D shape,
etc. you should probably do it with addChordShape and offset-fret to  use
the known shapes.

> patrick
> 
> P.S.: I always get two identical e-mails from you (but not from the others). I
> thought the mailing list prevents "double postings"?!

The gnu lists do, but the lilynet.net may not.

I'll try to remember to eliminate the reply to you directly, and just send
it to tablatures.

Thanks,

Carl