1. Use the left pedal for color
Purpose: distinguish a change of tone from simply playing more quietly. On a grand piano, the left pedal shifts the action; on a typical upright it moves the hammers nearer the strings. The effects are not identical. Digital instruments vary with their pedal system and selected sound.
The traditional directions una corda and tre corde ask for the shifted color and its return. The mechanism of a modern grand does not necessarily make the literal “one string” description true for every note.
Play the phrase at mp with the damper pedal up. Repeat with the left pedal depressed before the first attack. Compare tone, attack, and decay, not only loudness. Then try p by touch alone and compare that result with p plus the left pedal.
Keep touch responsible for the phrase
The left pedal is not a substitute for controlled quiet playing. Shape the line and balance the hands in either version. A phrase may ask for a veiled color without becoming inaudible, or for a clear soft sound without the left pedal.
Release the left pedal at a deliberate point before a new attack and listen to the return of the normal color. Avoid a sudden physical movement that disturbs posture or creates mechanical noise.
Checkpoint: describe the difference your own instrument produces. Do not assume that an upright, grand, and digital piano offer the same tonal effect.
2. Capture selected notes with sostenuto
A true sostenuto pedal retains the dampers of notes whose keys are held when it is engaged. Notes played afterward can remain detached. This differs from the damper pedal, which sustains subsequently played notes as well.
Not every middle pedal provides sostenuto. Many uprights use it as a practice mute or bass-sustain pedal. Check the instrument’s function before this exercise; a mute pedal cannot perform the selective-capture task.
- Play and hold the low C with the LH while the RH rests.
- Depress the middle sostenuto pedal before releasing that key. The marked eighth-note offset makes the capture sequence visible.
- Release the LH on beat 2. Confirm that the bass continues.
- Play the RH staccatos. They should stop when the fingers release while the captured C continues to decay.
- Lift the sostenuto on the final quarter rest to release the retained bass.
If the upper notes sustain too, check whether the damper pedal is down or the middle pedal has a different function. If the bass stops immediately, confirm that its key was still held at the moment of capture.
Checkpoint: one selected bass continues while later upper notes remain short. The bracket in this example controls sostenuto, not the right damper pedal.
3. Combine the pedals only for a reason
Sostenuto can retain a selected bass while the damper pedal clears changing upper harmonies. Learn each action separately before combining them. Capture only the intended notes: any other damped keys held at the capture moment may also be retained.
Try the previous exercise with one brief damper-pedal touch during the RH line. Release the right pedal while keeping sostenuto depressed. Hear the difference between the cleared upper notes and the continuing selected bass. Then release sostenuto as well.
Choose a practical alternative
If an instrument lacks true sostenuto, possible alternatives include holding a bass with a finger, redistributing notes between hands, adjusting a pedal span, or accepting a shorter resonance. These choices can alter articulation or texture; test the musical result rather than pretending they are exact mechanical substitutes.
The left pedal can be combined with either sustaining pedal when the desired color calls for it. Its job remains distinct: changing the attack and tone of new notes, rather than selecting which old notes are retained.
A final pedal checklist
- Right pedal: what sound should continue, and when should it clear?
- Partial depth: does a smaller movement produce the intended audible change on this instrument?
- Left pedal: what color do I want beyond a simple change of loudness?
- Sostenuto: exactly which notes should be captured, and are their keys held at that moment?
Transfer: practice the intended pedal and dynamic early in a piece’s preparation. Also use dry versions to diagnose finger timing and balance. The two approaches answer different questions; neither should become an excuse to postpone listening to the finished musical sound.