Instrument Transposition Chart Calculator

Enter a written MIDI note number and select your instrument (or enter custom semitones) to calculate the sounding concert pitch, interval name, and enharmonic spelling.

Created by Luis GonzalezLast updated: June 5, 2026

How to Use This Calculator

1
Enter the Written MIDI Note
Input the MIDI note number as it appears in the score. Middle C is 60; each semitone is +1 or -1.
2
Select an Instrument Type
Choose a common transposing instrument from the dropdown to auto-fill the transposition semitones, or select Custom to enter your own value.
3
Adjust Transposition (Semitones) if needed
The field auto-fills from the dropdown, but you can override it. Negative values mean the instrument sounds lower than written (e.g., -2 for Bb clarinet, -7 for F horn).
4
Review your results
Review the Sounding Note, Sounding MIDI, Written Note, Transposition Interval, Enharmonic Equivalent, and Semitone Difference. After calculating, use Recent to revisit previous scenarios.

Example Calculation

A composer needs to find the concert pitch of a Middle C (MIDI 60) written for a Bb clarinet, which transposes down by 2 semitones.

Written MIDI Note

Instrument Type

Bb instruments (trumpet, clarinet, tenor sax)

Transposition (Semitones)

-2

Results

Sounding Note

A#/Bb3; Sounding MIDI: 58; Written Note: C4; Transposition Interval: Major 2nd down; Enharmonic Equivalent: A#3 / Bb3; Semitone Difference: 2 st.

Tips

Use the Instrument Type dropdown

Select your instrument from the dropdown to auto-fill the correct transposition. Common presets include Bb (-2), Eb (-9), F horn (-7), and piccolo (+12). For unusual instruments, select Custom and enter the semitones manually.

Memorize common transpositions

Bb clarinet and trumpet transpose -2 (Major 2nd down), French horn in F transposes -7 (Perfect 5th down), and alto sax in Eb transposes -9 (Major 6th down). These cover most orchestral transposing instruments.

Use enharmonic equivalents wisely

The Enharmonic Equivalent card shows alternate spellings (e.g., A#3 / Bb3). Choose the spelling consistent with the key signature — in flat keys use Bb, in sharp keys use A#.

Check the register assessment

The Sounding Note subheader indicates the register (bass, middle, high). Ensure the sounding pitch falls within your instrument's practical range to avoid unplayable passages.

Unveiling Concert Pitches for Transposing Instruments

The Instrument Transposition Chart Calculator reveals the sounding concert pitch for any transposing instrument.

Enter a written MIDI note number, select your instrument from presets (Bb, Eb, F, and more), and the calculator converts written pitch to concert pitch instantly.

For a Bb clarinet playing written C4 (MIDI 60), the sounding pitch is A#/Bb3 (MIDI 58) — a Major 2nd lower.

This tool is indispensable for composers, orchestrators, and musicians working with transposing instruments.

The Semitone Logic Behind Transposing Instruments

The calculator applies a simple arithmetic operation to convert written MIDI notes to sounding concert pitch:

Sounding MIDI = Written MIDI Note + Transposition (semitones)

The result is then converted to a note name and octave.

Additional outputs include:

Written Note = note name for the Written MIDI Note
Sounding Note = note name for the Sounding MIDI
Transposition Interval = musical interval name for the semitone offset
Enharmonic Equivalent = alternate spelling of the sounding note
Semitone Difference = absolute value of the transposition

Written MIDI Note is the pitch as notated in the score (60 = Middle C).

Transposition (semitones) is the instrument's fixed offset — negative means it sounds lower (e.g., -2 for Bb clarinet, -7 for F horn), positive means higher (e.g., +12 for piccolo).

💡 To understand the direct relationship between MIDI numbers and note names, our Piano Key Number to Note Calculator can be a helpful companion.

Example: Transposing Middle C for a Bb Clarinet

A composer writes Middle C (MIDI 60) for a Bb clarinet, which transposes down by 2 semitones.

Written MIDI Note: 60 (Middle C, or C4).
Transposition: -2 semitones (Bb clarinet sounds a Major 2nd lower).
Sounding MIDI: 60 + (-2) = 58.
Sounding Note: MIDI 58 = A#/Bb3 (lower-middle register).
Written Note: MIDI 60 = C4.
Transposition Interval: Major 2nd down (2 semitones down).
Enharmonic Equivalent: A#3 / Bb3 — use Bb3 in flat keys, A#3 in sharp keys.
Semitone Difference: 2 st — sounds 2 semitones lower than written.

The Bb clarinet will produce an A#/Bb3 when a C4 is written in its part.

In an orchestral score in Bb major, the preferred spelling is Bb3.

💡 Beyond individual note transpositions, understanding broader harmonic relationships is vital. Our Parallel Major / Minor Calculator explores key relationships in music theory.

Common Instrument Transposition Reference

The calculator includes presets for the most common transposing instruments:

Concert pitch (C): 0 semitones — flute, oboe, piano, violin
Bb instruments: -2 semitones — trumpet, clarinet, tenor sax, soprano sax
Eb instruments: -9 semitones — alto sax, Eb clarinet
F instruments: -7 semitones — French horn, English horn (cor anglais)
G instruments: -5 semitones — alto flute
Bb bass: -14 semitones — bass clarinet (octave + Major 2nd down)
Eb bass: -21 semitones — baritone sax (octave + Major 6th down)
Octave transposing: -12 semitones — guitar, bass guitar (sound one octave lower than written)
Piccolo: +12 semitones — sounds one octave higher than written

Navigating Transposing Instruments as a Conductor or Arranger

Conductors and arrangers rely on transposition knowledge to read full scores and create accurate parts.

A conductor mentally converts each transposing part to concert pitch to hear the full harmonic texture, identify tuning issues, and balance dynamics.

An arranger must ensure each instrument's part sits within a comfortable, idiomatic range — writing a French horn part that's too high in concert pitch may produce strained, unmusical results even if it looks reasonable on the written page.

Use the register assessment in the Sounding Note subheader to verify that your transposed pitches fall within practical playing ranges.

Frequently Asked Questions

What is instrument transposition in music?

Instrument transposition means a written note in the score does not match the actual sounding pitch. Transposing instruments are notated at a different pitch than they sound, usually to simplify fingering across instrument families. For example, a C written for a Bb clarinet sounds as Bb (MIDI 58 instead of 60).

Why do some instruments transpose?

Instruments transpose for historical, ergonomic, and practical reasons. It allows musicians to use the same fingerings across different-sized instruments in a family (e.g., soprano, alto, tenor, and baritone saxophones all read the same fingering patterns). It also keeps notation within a readable range on the staff.

What is a MIDI note number?

A MIDI note number is an integer from 0 to 127 representing a specific pitch. Middle C (C4) is MIDI 60, and each semitone adds or subtracts 1. This standardized system lets digital instruments and software communicate pitch consistently, and this calculator uses it as input for precise transposition.

How does a French horn in F transpose?

A French horn in F sounds a perfect 5th (7 semitones) lower than written. When a horn player reads C4 (MIDI 60), the sounding pitch is F3 (MIDI 53). To get a concert C, the horn player must read G — 7 semitones higher than the desired sounding pitch.

What does the Enharmonic Equivalent card show?

It shows the alternate spelling of the sounding note. For example, MIDI 58 produces A#/Bb3, and the enharmonic card displays A#3 / Bb3 separately. Choose the spelling that matches the key signature of your piece — Bb in flat keys, A# in sharp keys.