Text: Subject: Re: [SVPForum] Music Question Date: Tue, 22 Jan 2002 22:25:10 -0000 From: "Lui Di Martino" Reply-To: SVPForum@yahoogroups.com To: Hi Dale As far as i know double and triple sharps/flats are used in order to keep scales looking tidy and readable. The rule is that , within a scale, one can only use a letter name once. But in some scales , in order to preserve the right intervals it is necessary to start using more than one sharp or flat. As you know all a sharp and flat really means is to moveback or forward by a semitone (say the 16:15 proportion within equal temperemant). So , three sharps on a letter (say Cx#) means we move forward from the C note by three semitones....C-# - D - D#. So C triple sharp (the x sign stands for double sharp) is just another way of saying D#. Double sharps etc are not needed usually within the first 12 Major and Minor scales. They do, though, occur at least once from then on. If you try and work out the scale of G# Major you will see this more clearly: G# A# B# C# D# E# Fx G# In order to keep the rule of only one letter allowed for a scale we need to use a double sharp on the note F. So, we have to use the formula of Tone-Tone-semi-tone etc for the Major scale and we can only use a letter once. Fx is really another name for the note G, but it wouldn't be allowed to be called G in the above scale. B# Cx Dx E# Fx Gx Ax (C) (D) (E) (F) (G) (A) (B) The letters in red show that the scale of B# Major is really the scale of C Major again. Although mathematically B# Major will be slightly different to C Major.....a case for tyhe Enharmonic perhaps? I can do some searching on the web for any other explanations but , unless the books and magazines have been misleading I believe that is the only use for the sharps and flats. I am a bit ill at the moment so I am going back to bed! I hope this is sufficient. As said, we apply the Major scale formula which could be written 1:1 - 9:8 - 5:4 - 4:3 - 3:2 etc, or: T (9:8)- T - S (16:15)- T - T - T - S BW...the reason a diminished chord can have a formula like 1 b3 b5 bb7 is because it's 'defaults' are 1 3 5 7 , so it is t6hese numbers that need to be accented or note. In the case of the chord C diminished it becomes these notes when the above formula is applied: C Eb Gb A So, the bb7 is really another name for the Major 6th interval. Yet it would have been not quite right to have referred to it as that, when what has happened is that the 7 has been flatted and flatted again! 1 3 5 7 C E G B (C MAj 7th) 1 3 5 b7 C E G Bb ( C Dom 7th) 1 b3 5 b7 C Eb G Bb (C Min7) 1 b3 b5 b7 C Eb Gb Bb ( C Min7b5) 1 b3 b5 bb7 C Eb Gb Bbb ( C Diminished 7)

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