In the bass
Targets often need different treatment than a simple pitch-only reading suggests.
Concept guide
What is stretch tuning on piano.
Stretch tuning is the practical adjustment that makes octaves sound right on real acoustic pianos, whose strings do not behave like ideal mathematical lines.
Why stretch exists
- Real piano strings have stiffness, not ideal behavior.
- That stiffness shifts partial relationships across the keyboard.
- If you tune purely to equal-temperament math, octaves can sound wrong.
- Stretch tuning compensates so the instrument sounds more musical.
What this means in practice
In the treble
High notes often need stretch consideration to keep octave relationships convincing.
Across the whole piano
The better the stretch map matches the instrument, the more natural the finished tuning feels.
How Tempera helps
- Sample the piano instead of assuming one fixed curve.
- Inspect stretch behavior in the Lab.
- Use the sampled context during the tuning workflow.
- Save the result with the piano profile for later visits.
Frequently asked questions
Is stretch tuning the same on every piano?
No. Different instruments can require different stretch behavior.
Why not tune every note exactly to equal temperament?
Because real acoustic pianos introduce inharmonicity that changes how intervals are perceived.
Do I need stretch sampling for every instrument?
For more repeatable acoustic work, sampling gives better context than relying on a generic assumption.
Use Tempera to sample stretch behavior, not guess it.
Install Tempera if you want stretch-aware workflow built into your iPhone tuning process.