Re: custom key signatures

[james]

On Sep 2, 2012, at 11:46 PM, Keith OHara wrote:

> james <james.lilypond <at> googlemail.com> writes:
> 
>> I'm looking at the new options for custom key signatures,
> 
>> "Accidentals in the key signature may be printed in octaves other than 
>> their traditional positions, or in multiple octaves, by using the flat-
>> positions and sharp-positions properties of KeySignature. Entries in 
>> these properties specify the range of staff-positions where accidentals 
>> will be printed. If a single position is specified in an entry, the 
>> accidentals are placed within the octave ending at that staff position."
> 
> This feature is new with development version 2.17.1.  It is meant for normal 
> key signatures, but it also works for custom key signatures of the simpler 
> type where you do not specify the octave explicitly.
> 
>> Does this mean that if a custom key signature is used with, say, 
>> g-flat and a-flat (for bass clef), the key is c major?
> 
> No.  The "\key g\major" (or the individually-specified flats and sharps) 
> determines the key.  The *-positions adjust where the key-signature 
> alterations are printed on the staff.
> 
> If you define an unusual key signature with G-flat and A-flat
> 
> \new Staff { \clef bass
>  \set Staff.keySignature = #`(( 4 . ,FLAT) ( 5 . ,FLAT))
>  f4 ges as b }
> 
> normally the flats go at the bottom of the staff, because that is their 
> position when they live with Bflat Eflat and  Dflat in traditional key 
> signatures.  This looks a little odd with just the G- and A-flat, so if 
> you like you cay say "please print flats on this Staff as close as you can 
> to the first space above the staff (position 5)"
> 
>  \override Staff.KeySignature #'flat-positions = #'(5)
> 
Ah, okay, so the space below the first line is 0, and the rest of the positions 
are calcluated up from that. Thanks!