What is a double flat?

Discussion in 'Music [DB]' started by lermgalieu, Dec 4, 2001.

  1. lermgalieu

    lermgalieu Supporting Member

    Apr 27, 2000
    Austin, TX
    Pardon my ignorance, but what does it mean when there are two flats (bb) in front of a note? It's all over the place in Rufus Reid's book (usually on diminished chords) so I want to make sure I am playing the right notes. It's not in the legend. Does that mean the flat of a flat - a whole step down? I don't think so, since for example in a Cdim7, he marks a B with this double flat, however I believe in Cdim7 it's a Bb, straight up (a dim 7 is a flat 5,3, and 7, right??). So could someone explain this notation to me? I thought I was seeing double...

    Is he telling me to play with poor intonation? ;-)

    thanks,

    Lawrence
     
  2. A double flat is an oboe and a bassoon playing in unison.
     
  3. Don Higdon

    Don Higdon In Memoriam

    Dec 11, 1999
    Princeton Junction, NJ
    b = 1/2 step lower
    bb = two 1/2 steps lower = one whole step lower.
    Bbb sounds like A
     
  4. lermgalieu

    lermgalieu Supporting Member

    Apr 27, 2000
    Austin, TX
    ok - then I guess my idea of a diminished 7 is wrong. The 3,5, AND the dominant 7 are all flatted then. Is that right?
     
  5. Don Higdon

    Don Higdon In Memoriam

    Dec 11, 1999
    Princeton Junction, NJ
    dim 7th on C = C, Eb, Gb, Bbb

    What you're describing C, Eb, Gb, Bb is called a half diminished by some. I've also heard it called Cm7 b5.
     
  6. Chris Fitzgerald

    Chris Fitzgerald Student of Life Staff Member Administrator Gold Supporting Member

    Oct 19, 2000
    Louisville, KY
    Right. half diminished 7th chords are also known as min7b5, but fully diminished 7th chords are just a stack of minor 3rds. i.e. - C, Eb, Gb, Bbb (A), ....or C#, E, G, Bb. Because they're symmetrical, there are only really three different fully diminished 7th chords...everything else is an inversion of one of the three.
     
  7. lermgalieu

    lermgalieu Supporting Member

    Apr 27, 2000
    Austin, TX
    Got it. Is there any other notation besides min7b5 to mark a half diminished?
     
  8. Chris Fitzgerald

    Chris Fitzgerald Student of Life Staff Member Administrator Gold Supporting Member

    Oct 19, 2000
    Louisville, KY
    Yes: a circle with a slash through it. There's actually a name for that symbol, but I can't think what it is.