If I have a flat for a note in the key signature, and then in a bar the same note with an flat symbol, does that mean the note is "double flatted"?
For example in the key of D Minor with hash one flat (B♭): This means that all B's are actually B♭'s. But if I have a B♭ in a bar , does that mean it's actually B♭♭ (A)?
Another example:
Here it is the third note that has a flat by itself as well as in the key signature.
No, it is still a B♭ as the accidentals in the key signature and measure are never additive. The flat is just reminding you that the B is flat. This is known as a courtesy accidental and is typically done if the previous measure uses a B that was different then the one in the key signature or if there was a different quality of B used in the measure it is used to cancel out the other quality.
In the key D minor, if you were ascending from A to D, a typical melody would be A, B, C♯, D. If you were descending in the next measure back to A, your melody would be D, C, B♭, A. It would be typical to remind you the C is natural and B is flat.
In your example, the flat is to show you the 9th of the chord is flat even thought it is in the key signature. Also, the chord is wrong since a D(b9) has an F♯ in it instead of an F, so the chord is actually a Dm(b9).
The accidental ♭ does not combine with the ♭ in the key signature to produce a double-flat. Rather, the accidental is redundant. The easiest interpretation rule is that any accidental overrides whatever is in the key signature.
The term for such usage is courtesy accidental:
Although a barline is nowadays understood to cancel the effect of an accidental (except for a tied note), often publishers will use a courtesy accidental (also referred to as a cautionary accidental or a reminder accidental) as a reminder of the correct pitch if the same note occurs in the following measure. This usage varies, although a few situations are construed to require a courtesy accidental, such as
- when the first note of a measure had an accidental applied to it in the previous measure
- after a tie carries an accidental across a barline, when the same note appears again in the subsequent measure.
No it indicates B flat. Usually the flat is cancelling a natural (or sharp) earlier in the measure. Even if it's not cancelling, it has only been included by the editor to improve the readability of the passage.
No, a B marked with a single flat will only ever be a B-flat.
Occasionally in written music you will see "courtesy accidentals", redundant accidentals meant to clarify or remind the player. These are are often used when a note was altered in a previous bar.
No, a Bb is a Bb, no matter how many times you say so!
One would be required if there had previously been a B natural, in the same octave, in the same bar. If it had been in a different octave, one (maybe in brackets) would seem sensible. In a preceding bar - use your common sense.
Your accidentals (flats or sharps) will add to whatever the key signature specifies. But they generally only affect the musical bar they are appear in, not the entire piece, unless they are then indicated again in many subsequent bars. But why write this complex way? You probably should be writing it in a different key, to get rid of so many accidentals that get indicated, then cancelled next bar, then reintroduced in future bars, making it a nightmare to try and play the piece.
