1. Coordinate the thumb with the moving hand
Purpose: make a fingering change without a bump, hesitation, or forced reach. “Thumb under” describes a relationship between fingers; it should not imply that the rest of the hand and arm must remain fixed while the thumb does all the traveling.
The RH below practices E–F with fingers 3–1. The LH descends A–G with fingers 3–1. The hands have different note patterns: practice them separately before trying them together.
Work slowly enough to hear the join
- Play the first two notes at p. Prepare the thumb’s destination while allowing the hand to move toward it.
- Continue through the thumb note and the following note. Listen for an unintended thumb accent or a longer gap.
- Reverse the four-note group. On the return, coordinate the finger passing over the thumb with the hand’s movement.
- Repeat at mf, keeping the same timing and a free wrist.
At this speed, some thumb passage beneath the hand may be useful. The objective is a comfortable connection, not the largest possible tuck. Do not pin the previous finger down after its musical duration has ended.
Checkpoint: the crossing note belongs to the phrase. A listener should not hear a new accent simply because the fingering changes from 3 to 1.
2. A larger gap needs more travel
The arpeggio fragment increases the distance around the change of position. In the RH, G4–C5 uses 3–1; in the descending LH, E3–C3 uses 4–1. These fingers match the C-major arpeggio pattern used earlier in the book.
Let the hand arrive with the thumb
Practice the two notes around each crossing, then add one note before and one after. Notice how the whole hand changes position. Avoid trying to reach the destination with the thumb while leaving the forearm behind.
Compare a comfortably detached version with a more connected version. The detached version makes timely release easier to observe; the connected version asks how smoothly you can join the sounds without strain. Neither requires freezing the hand at the departure point.
The returning finger-over movement also needs room. In the RH return, prepare finger 3 for G while releasing the thumb’s C at the appropriate time. In the LH return, prepare finger 4 for E while the hand moves upward from the thumb’s C.
Choose the sound before adding speed
Keep a clear pulse and a specified dynamic. If the thumb produces a repeated accent, practice the crossing softly in a short group before restoring the full phrase. If the connection requires an uncomfortable stretch, use a freer release and review the route rather than forcing it.
Checkpoint: both directions work, the notes after the crossing are prepared, and the hand does not remain twisted after the group ends.
3. Adapt the movement to tempo and articulation
There is no single visible motion that fits every scale, arpeggio, hand size, and tempo. Slow finger connection, fast light passagework, and deliberately detached notes place different demands on timing and release.
As the tempo rises, the sideways travel of the hand and arm becomes especially important. A deep, slow thumb tuck can obstruct a fast passage. Equally, “never pass the thumb under” is too rigid a rule for all situations. Seek a movement that serves the written sound and leaves the next position ready.
A controlled comparison
Use the four-note RH group from the first page.
- Play it slowly and connected at p. Notice the thumb’s preparation and the hand’s sideways movement.
- Play the same notes detached at the same tempo. Keep the arm free to travel as each note releases.
- Return to a connected musical intention and increase the tempo slightly. Allow the movement to become smaller and more continuous rather than exaggerating the slow-motion demonstration.
- Stop after a short group. Check that the hand can release comfortably, then repeat only if the sound remains even.
Do not speed up to hide an unreliable join. Record a short attempt and listen for timing and tone across the crossing; the motion’s appearance alone cannot establish whether it works.
Return to full patterns
Apply the same process to one scale and one arpeggio already learned. Mark each position change and practice its neighboring notes in both directions. Preserve the printed fingers unless a considered alternative suits the passage and hand better.
For a real piece, include its articulation and dynamic from the start. A legato cantabile passage and a light detached run may use the same fingers with different release timing.
Transfer: use the fingering chapter’s decision process when a standard pattern does not fit the musical context. Comfortable movement, reliable rhythm, intended articulation, and preparation of the next notes all matter.