A transposing instrument reads music written at a different pitch than it sounds. The written part is shifted so the player’s fingerings stay consistent across the family, while a piano (a concert-pitch, non-transposing instrument) sounds exactly what is on the page. That mismatch is why a Alto Flute (G) playing from a piano’s sheet music will sound in the wrong key unless the part is transposed first.
Written → concert notes
What each written note sounds like at concert (piano) pitch on the Alto Flute (G):
| Written note | Sounds (concert) |
|---|---|
| C | G |
| D | A |
| E | B |
| F | C |
| G | D |
| A | E |
| B | F♯ |
Key-signature conversion (concert → written)
To turn a piano (concert) key into the Alto Flute (G)’s written key, move up a perfect fourth:
| Concert (piano) key | Written key |
|---|---|
| C major | F major |
| G major | C major |
| D major | G major |
| A major | D major |
| F major | B♭ major |
| B♭ major | E♭ major |
| E♭ major | A♭ major |
| A♭ major | D♭ major |
Why the Alto Flute (G) is pitched in G
Instruments in a family are built in different keys so a player can move between them without relearning fingerings. On the Alto Flute (G), the same fingering that produces a written C sounds concert G; writing the part up a perfect fourth lets the player keep those familiar fingerings. For the pianist, the practical takeaway is the reverse: hand a Alto Flute (G) player your concert-pitch music transposed up a perfect fourth, or you’ll be a perfect fourth apart.
Alto Flute (G) transposition — FAQ
What does written C sound like on the Alto Flute (G)?
How do I transpose a piano part for the Alto Flute (G)?
What key is the Alto Flute (G) in?
Related
Conversions are computed from the instrument’s transposition interval using interval math, not a hand-typed table, so every enharmonic spelling is correct.