Trying to get a basic grasp of intervals but something is confusing me. If I understand correctly what I've read then it means that there is a different name for C-G (perfect fifth?) and C-Abb (diminished sixth?).
Is this correct? If so, how can I ever name an interval without having the sheet music at hand? If not, where did I go wrong? Thanks a bunch in advance!
You're correct, Arjen, in order to be absolutely certain that what you're seeing is one thing and not the other you need the sheet music.
However, it is very rare when a composer is going to use a dim-6 instead of a 5, or a dim 4 instead of a maj 3, etc. So if you don't have the music in front of you, unless there's something in the chords or melody to suggest otherwise, you're usually pretty safe going with the most common interval name.
"The music business is a cruel and shallow money trench, a long plastic hallway where thieves and pimps run free, and good men die like dogs. There's also a negative side." -- HST
Yes, you're correct.
Intervals can have several names... you're only scratching the surface!
C-G = perfect fifth
C-Fx = doubly-augmented fourth
C-Abb = diminished sixth
B#-Fx = perfect fifth
B#-G = diminished sixth
Dbb-Abb = perfect fifth
Dbb-G = doubly-augmented fourth
B#-Abb or Dbb-Fx are possible too, but even theorists aren't crazy enough to name those :)
It really depends on context - your upper note is measured in the key of the lower note. Since it hinges on key, you have to settle on the names before you can identify the interval.
It's actually pretty rare to use anything but major/minor/augmented or perfect/augmented/diminished, though, because you want your notation to be clear - that's why chords like a fully diminished seventh (1-b3-b5-bb7) are normally written out enharmonically (1-b3-b5-6). We understand it's a diminished seventh, but we sure like to see a major sixth when we're sight reading!
So it's more like... if it sounds like a perfect fifth, why not change the accidentals to write it that way? That's what's done in the real world of transcriptions, and the multiple names only find their way into theory books and formal analysis.
Guitar teacher offering lessons in Plainfield IL
Cool, thanks guys. Haven't ever heared of doubly augmented/diminished intervals before but I assume that's just with the top note one semitone higher/lower then the standard augmented/diminished intervals.
So it's more like... if it sounds like a perfect fifth, why not change the accidentals to write it that way? That's what's done in the real world of transcriptions, and the multiple names only find their way into theory books and formal analysis.
I'm preparing for exams and I know they'll ask things like this. It's not really about practical use I guess but they just want me to know what I'm talking about from a theoretical perspective.
Thanks again, cleared it up in my head. :)
