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Invention No. 9 in F minor, BWV 780

Johann Sebastian Bach (1685–1750) · sheet music

  • Key F minor
  • Time 3/4
  • Levels 7–9
  • Passages 2

Your turn · both hands

 

 

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Johann Sebastian Bach, German baroque (1685–1750). The reading release has 2 passages from this piece at levels 7–9; the reader above opens on the easiest, bars 29–32 for both hands together.

Practice the hard bars →

The hardest stretch is bars 5–8 at level 9.

Your practice path

Learn it the way teachers do: each hand on its own, then together, then the hard bars. Each step is a real graded passage of Invention No. 9 in F minor, BWV 780.

  1. Hands together · bars 29–32 level 7
  2. The hardest bars · bars 5–8 level 9

How to play Invention No. 9 in F minor, BWV 780

  1. Tempo:The score has no tempo mark. A PTNA commentator advises a rather slow pace, and PTNA lists about a minute and forty seconds in all; choose a calm three in which the sixteenths stay even.
  2. Right hand:The right hand opens with the subject: falling sixteenths that come to rest on longer notes. Shape each four-bar statement as one phrase, rising toward its high point and relaxing afterward.
  3. Left hand:When the subject passes to the left hand, give it the same shape and tone it had on top, and let the right hand's counter-subject sit just below it in volume.
  4. Hands together:At each voice exchange the accompanying hand must take over the tune without a change of color. Play the handover points hands together at half speed until they sound seamless.
  5. Fingering:Plan fingerings ahead through the long sixteenth lines so no awkward thumb crossing breaks the legato, and keep the same choices every time.
  6. Reading:Four flats plus naturals such as E, D, and A natural make this harder to read than to play. Name the altered notes in each chromatic run before playing it.
  7. Dynamics:Bach wrote no dynamics; a PTNA commentator suggests letting each statement of the subject grow toward its peak and fall away, varying the color as the subject changes key.
  8. Practice:Practice each subject entrance on its own, then join it to the counter-subject. End each session with the whole opening at a metronome setting slower than feels necessary.

Common mistakes

  • Letting the left-hand sixteenths grow louder than the subject. Fix: Play the left hand at a clearly softer level and listen to the top line first.
  • Speeding up through the stepwise sixteenth runs. Fix: Keep a steady metronome click and make the end of each run as even as its beginning.
  • Treating the chromatic notes as accidents instead of part of the melody. Fix: Sing or hum the subject, so you hear where the half steps belong.
  • Detaching notes inside a phrase. Fix: Practice legato slowly, lifting only at phrase ends.

Structure: two-section invention with voice exchange

The piece divides into two sections. In the first, the upper voice states the long subject over a counter-subject, the voices then swap roles, and the music modulates using both ideas. The second section reverses the opening, with the lower voice stating the subject in the dominant before the music returns to F minor.

A · Subject and counter-subject (F minor)
The subject falls in sixteenths and settles on longer notes while the counter-subject answers with a leap and its own running line. Both hands read close, mostly stepwise lines.
B · Voice exchange and modulation
Subject and counter-subject change hands and are reused as the harmony moves; accidentals such as E natural and D natural pile up as the key center shifts.
C · Second section (C minor (the dominant), returning to F minor)
The lower voice now leads with the subject in the dominant, so the left hand carries the main melodic line.

About Invention No. 9 in F minor, BWV 780

Bach arranged the inventions in rising order of key, and this ninth one is in F minor. A PTNA commentator calls F minor a serious, sorrowful key for many composers, and this piece, with no tempo or dynamic marks in the score, is usually taken at an unhurried pace.

Its subject is comparatively long for the set, spanning four bars, and the other voice accompanies it with a counter-subject. PTNA's Yusuke Takamatsu notes that the expressive melody suits the cantabile manner Bach names on his title page as one aim of the collection.

The music reached print in 1801 in a volume titled 15 Inventions, where this piece is the ninth. IMSLP lists arrangements of it for four cellos, two recorders, two guitars, and clarinet with violin, among others.

  • Its subject runs four bars, unusually long among the two-part inventions.
  • Right after the first statement, the voices swap: the subject moves to the lower voice and the counter-subject to the upper.
  • A PTNA commentator suggests a rather slow tempo and warns that playing it slowly makes it musically harder, even though the fingerwork is not difficult.
  • Bach's title page says the collection should give learners a strong foretaste of composition, as well as practice in playing two voices cleanly.

Why the first passage is level 7

That passage is level 7 rather than 6 because its key signature has 4 sharps or flats, a hand covers more than one position, it has syncopated rhythms, it runs fast figuration.

Four flats and chromatic steps in long sixteenth-note lines make accidentals the main reading challenge. Both hands stay fairly close to the staves, with only occasional ledger lines.

Questions about Invention No. 9 in F minor, BWV 780

How hard is Invention No. 9 in F minor, BWV 780 to play?
Its passages grade from level 7 to level 9 on Real Sight Reader's ten-level reading scale, so the full piece is intermediate to advanced reading. The hardest stretch is bars 5–8 at level 9.
Is there an easy part of Invention No. 9 in F minor, BWV 780 for beginners?
Its easiest passage is level 7, so it suits a reader past the beginner stage. Start with bars 29–32 for both hands together, the level-7 passage in the reader at the top of this page; it is level 7 because its key signature has 4 sharps or flats and a hand covers more than one position.
What key and time signature is Invention No. 9 in F minor, BWV 780 in?
Invention No. 9 in F minor, BWV 780 is in F minor, 4 flats. The engraving on this page is in 3/4 time.
Who composed Invention No. 9 in F minor, BWV 780?
Johann Sebastian Bach, German baroque (1685–1750). Bach arranged the inventions in rising order of key, and this ninth one is in F minor.
Can I practice Invention No. 9 in F minor, BWV 780 online for free?
Yes. The reader on this page plays any of the 2 graded passages from Invention No. 9 in F minor, BWV 780 in your browser, with an on-screen keyboard or a MIDI keyboard, and marks every note as you play. No signup.
Why does Invention No. 9 sound so sad?
It is in F minor, which a PTNA commentator calls a serious, sorrowful key for many composers, and its slow, falling subject reinforces that mood.
How long is Bach's Invention No. 9?
The PTNA Piano Music Encyclopedia lists about 1 minute 40 seconds.
Is this invention the same as a sinfonia?
No. The inventions are two-voice pieces and the sinfonias use three voices; Bach collected both types in one set.

Every passage, easiest first

The reading release grades 2 distinct passages of this piece. Open any of them in the reader:

Level 7
bars 29–32 both hands
Level 9
bars 5–8 both hands

More pieces to sight-read

Score: public-domain engraving from the corpus (pdmx), graded by the piano-reading-v2-20261023-identity-audit reading release.

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