Invention No. 3
D major in perpetual motion.
Among the fifteen two-part Inventions Bach gathered for his son Wilhelm Friedemann's Clavier-Büchlein around 1720, No. 3 in D major is the most overtly brilliant. The key of D major carried connotations of fanfare and ceremony in the Baroque era - it was the key of trumpets and drums - and Bach channels that brightness into an Invention driven almost entirely by triplet eighth notes that give it an almost breathless forward momentum.
The piece's contrapuntal device is sequential imitation: the opening triplet figure is answered by the left hand while the right hand continues spinning new material above it, creating a texture of layered motion rather than strict call-and-response. Where No. 1 teaches imitation through clarity, No. 3 teaches it through speed, asking the player to keep both voices audible even as the notes come faster.
Keep both voices bright in the rush.
The danger in this piece is that the triplets blur into one undifferentiated stream. Practice each hand alone at 50% tempo, exaggerating the accent on the first note of each triplet group to lock in the rhythmic shape. When combining hands, focus specifically on the measures where both voices move in parallel thirds or sixths - those require the most precise synchronization and reward careful slow work.
Before you practice.
01 Is Bach Invention No. 3 harder than the other inventions?
Its 60-bar length and continuous 3/8 triplet motion make it one of the more demanding late-beginner inventions for stamina and evenness, even though the hand independence required is not unusually complex. Pianists who handle simpler inventions comfortably will find it a satisfying but genuine step up in endurance.
02 How long does it take to learn Bach Invention No. 3?
Budget six to ten weeks of daily practice for a clean hands-together run at tempo. The main challenge is sustaining even, lightly articulated triplets all the way to bar 60, so slow hands-separate work early on pays dividends later.
03 What technique does Invention No. 3 develop?
It builds finger evenness, clean articulation, and the rhythmic stamina needed to sustain a consistent pulse across a longer piece - skills that carry over directly to Baroque dance suites, sonatinas, and any repertoire that demands a steady, even touch.
Triplets need an anchor note.
At 50% tempo, accent the first note of each triplet and listen for the group shape before speeding up. Use the section loop on any four-measure run where the voices cross or converge - those passages sound effortless at full tempo only after they have been isolated and worked carefully. Wait-for-note is off for now, so playback will not pause for your input.
