Bach-Lehman Temperament vs. Equal Temperament
Compare the tuning characteristics of Bach-Lehman Temperament and Equal Temperament — cent deviations per note, practical guidance, and historical context.
At a Glance
| Feature | Bach-Lehman Temperament | Equal Temperament |
|---|---|---|
| Category | well-temperament | equal |
| Formula Type | cent-offsets | equal-division |
| Historical Era | Baroque | Modern |
| Key Advantage | All keys in the WTC are singularly in tune; key characters precisely match Baroque affect theory. | All 12 keys are equally in-tune — transpose freely without re-tuning. |
| Key Limitation | The reconstruction remains debated — not universally accepted as Bach's intended tuning. | Pure fifths (2 cents flat) and major thirds (14 cents sharp) are slightly impure in every key. |
| Typical Use | Well-Tempered Clavier and Bach keyboard works performed with historical awareness. | Standard tuning for all modern Western instruments since the 20th century. |
Cent Deviations: All 12 Notes vs. Equal Temperament
Positive cents = sharper than equal temperament. Negative = flatter. Difference column shows Equal Temperament minus Bach-Lehman Temperament: positive means Equal Temperament is sharper.
| Note | Bach-Lehman Temperament (¢) | Equal Temperament (¢) | Difference (¢) |
|---|---|---|---|
| C4 | +5.87 | 0.00 | -5.87 |
| Db4 | +3.91 | 0.00 | -3.91 |
| D4 | +1.96 | 0.00 | -1.96 |
| Eb4 | +3.91 | 0.00 | -3.91 |
| E4 | -1.96 | 0.00 | +1.96 |
| F4 | +7.82 | 0.00 | -7.82 |
| Gb4 | +1.96 | 0.00 | -1.96 |
| G4 | +3.91 | 0.00 | -3.91 |
| Ab4 | +3.91 | 0.00 | -3.91 |
| A4 | 0.00 | 0.00 | 0.00 |
| Bb4 | +5.87 | 0.00 | -5.87 |
| B4 | -1.96 | 0.00 | +1.96 |
When to Choose Each
Choose Bach-Lehman Temperament when:
Choose Bach-Lehman Temperament for Baroque keyboard repertoire spanning multiple keys — especially works that tour the circle of fifths. Its varied key color gives each tonality a distinctive musical character.
Choose Equal Temperament when:
Choose Equal Temperament for modern ensembles, fixed-pitch instruments (piano, guitar, wind instruments), and any music that modulates freely across all 24 keys. It is the universal standard for contemporary Western music.
Historical Context
Well temperaments emerged in the Baroque era as practical compromises enabling all 24 keys, while Equal Temperament achieved true key equality only in the 20th century. J.S. Bach's Well-Tempered Clavier (1722) may have been composed with a specific well temperament — not equal temperament — in mind.
- Bach-Lehman Temperament
- Developed by Bradley Lehman reconstruction (2005), attributed to J.S. Bach — Baroque era
- Equal Temperament
- Developed by Theoretical development (12-TET standardized c. 1900) — Modern era
Compare Temperaments in Tunable — Get Tunable.
Tunable supports Bach-Lehman Temperament, Equal Temperament, and 14 other tuning systems. Hear the difference in real-time as you play.
