I just play guitar and harmonica, but I understand that some instruments are considered transposing instruments. Nobody has ever explained the reasons for transposing instruments other than they are tuned differently. I'd like to know what the differences are and the reasons for those differences. Can anyone explain in every day language and help me understand?

  • music.stackexchange.com/questions/7225/… and music.stackexchange.com/questions/5374/… might be helpful? I think the main 'logical' reason is so that players can play similar instruments that play in different ranges (because the instruments are 'smaller and larger versions of each other') easily by relating each note on the score to a finger position. Commented May 20, 2018 at 21:28
  • @topo morto - Are things moving toward a more standardized way of doing things, or is this way pretty much set in stone. I might be able to better understand it if I take one thing at a time, but just trying to imagine the whole idea seems quite confusing. Commented May 20, 2018 at 21:56
  • AFAIK the tradition of certain instruments being notated transposed is fairly well established, but like you I don't actually play any transposing instrument.... it took me a while to get the idea! Commented May 20, 2018 at 22:01

2 Answers 2


There’s certainly some historical stuff going on; some instruments are transposing more out of tradition than need. For example, the horn (or French horn if you prefer) is a transposing instrument because, before the invention of valves, horns would have to be modified to be in many different keys. A horn in C could only play the notes of the C overtone series (more or less), and so wouldn’t be too useful for a piece in the key of Eb. Horn player had many different lengths of tubing (called crooks) which they could remove or insert or substitute to change the key of the instrument to fit the composition. However, they didn’t want to have to learn entirely different fingerings for all of those different keys, so the notation just pretended that the instrument was always in C. When the horn was a C horn, C was a C. When the horn was an Eb horn, C was an Eb. When the horn was an F horn, C was an F. The same fingering was always used for “C”, the tubes would just alter “C” to be whatever pitch was necessary. [see note below]

The modern horn is always in F, so theoretically we could change the notation system, but F tuning is what all of them know and are used to. However, some instruments still do get used in multiple keys. All of the different saxophones are different transpositions and have different ranges, but thanks to the magic of transposition, the notation always lines up with fingerings in the same way. Same deal for all of the clarinets and all of the trumpets. A particular notation always indicates the same fingering, even though the pitches that come out vary substantially. The burden is on the notater to figure out the proper written notes to get the sound they want, rather than the performer. This makes sense, because the notater generally has all the time in the world, while the performer is also trying to play correct rhythms, proper dynamics, expression, etc.

[As Phoog points out in the comments, my wording here is false because natural (i.e. valveless) horns don’t have fingerings, that’s the whole point. I’m having trouble thinking of a better way of saying it, especially one that maintains parallelism with the second paragraph, in which “fingerings” is the right word. On a natural horn, pitch is controlled by the embouchure and the airspeed among other less tangible techniques, but the central point is the same: on some level, seeing a “C” means the same performance parameters regardless of the sounding pitch. ]

  • 1
    "The same fingering was always used for “C”" (speaking of horns): there is no fingering on a natural horn.
    – phoog
    Commented May 21, 2018 at 5:12
  • @phoog Ah, right, good point. I think my meaning comes across, but that was poorly said. Commented May 21, 2018 at 10:51

Most transposing instruments not transposed by whole octaves have controls corresponding to a diatonic scale. Standard notation associates notes without accidentals with the C major scale, the white keys on a piano. An instrument that has its "white keys" on a different scale will be more naturally to play in transposing notation: that saves the player the same kind of headache that tablature saves a guitar player: having to deal with a less straightforward relation of notation to fingering action.

  • Sorry - completely wrong. Check out one of the duplicate questions mentioned in comments above.
    – Laurence
    Commented May 20, 2018 at 23:37

Not the answer you're looking for? Browse other questions tagged or ask your own question.