Show off your theory chops with my weekly challenge! You’ll find a new question here every Monday. Please comment to post your reply.
This week’s challenge:
These are the octaves that open Beethoven’s last piano sonata, Opus 111 in C minor. What interval do they form, and what interval is enharmonic with this one?
Listen to the Audio:
Check back Friday, June 11th for the answer!
ANSWER for 6/7/21
This is a diminished seventh. It’s enharmonic with a major sixth, but the spelling of E flat down to F sharp makes it a seventh. Letter name spelling always determines what an interval is called. When naming an interval, always start with letter names before considering the flats and sharps. Any kind of E (E natural, flat, or sharp) down to any kind of F is a seventh. Then look at the number of half-steps in the interval. A major seventh is eleven half-steps, a minor seventh is ten, and a diminished seventh is nine. It sounds the same as a major sixth, but spelling is everything! It determines not only the interval’s name, but also how it functions in music.
Intervals are like the atomic building blocks of music, and I have complete interval lessons in the Fundamentals Module! Sign up for a monthly subscription for full access to all video lessons, worksheets, and answer keys. Also, this year I’ll be adding new lessons on modes. I created Breaking Barlines with one thing in mind: making music theory effective and FUN!
Charles Birkby says
It’s a dim7, enharmonic with a Maj6.
Aron Bernstein says
You, sir, are interstellar with intervals! Well done!