Topmusicanswers
The purpose of double sharps and flats in key signatures is to represent this scale in the way it is written, and avoid constant use of accidentals on a note - as per the example switching between G and G#.
- What is the purpose of double flats?
- Why are there both sharps and flats?
- Why don't we use double flats or double sharps in major scales?
What is the purpose of double flats?
A double-flat is the equivalent of two flats, and lowers a note's pitch by two half steps. The double-flat symbol (♭♭) is placed before a note like other accidentals.
Why are there both sharps and flats?
Altered notes want to continue in the direction in which they have been altered. Sharps indicate a raised note and the direction it wants to resolve. Flats indicate a lowered note and the direction it wants to resolve. Accidentals when written correctly, make lines easier to read.
Why don't we use double flats or double sharps in major scales?
The reason that we have double-flats is a bit more complicated, since there are no scales that require us to modify existing notes by lowering notes. But there are chords that require us to lower the 7th note by placing a flat in front. If that key's 7th note is already flat, then you'd need to use a double-flat.
