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What is a simple way to accomplish transposing a song from one key to another key?

In other words if I am looking at a song written in the key of C and can't sing it in that key and I want to transpose it to a different key, how would I go about finding the correct melody notes for the new key so that the melody stays the same - only in a different key where I can sing it?

  • 2
    This question is at least very related. – Matt L. Apr 5 '16 at 7:34
  • @MattL. It is related - but that question is specifically about writing an algorithm for computer code for a software program to transpose. It would not be useful to a musician who simply wants to transpose a piece from one key to another. The solution to that question is far to complex than it needs to be for simple transposing work. – Rockin Cowboy Apr 5 '16 at 17:51
  • What instrument? If you're doing it on the fly, there are tips and techniques that are very instrument specific. On a string instrument (guitar, violin, etc), you can just play further up the neck without even thinking about notes, but on a woodwind, you actually have to know what different fingerings to use. – Karen Apr 7 '16 at 11:49
  • @Karen I posed the question as a general transcription question. Tim's answer makes the point you suggested relative to guitar and it would be valid for all stringed instruments if open strings are not part of the equation. See my comment to Tim's answer below. Your point is certainly well taken - thanks for the comment. – Rockin Cowboy Apr 7 '16 at 23:34
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Once a melody is composed and written in one key using the notes from said key's corresponding scale, that same melody can then be "transposed" (converted) to any other key that exist in Western music.

The process of composing any piece of music follows a strict methodology. Below I will explain the process of transposing any piece of music from one key to another.

If a composition is based on the C Major scale it is likely that all of the notes (exceptions are possible) will be found in the key of C. Each note in a given key can be reduced to and defined by what we call corresponding scale degrees. Each diatonic scale in Western Music is comprised of 7 notes.
The C Major scale for example contains the following 7 notes - C D E F G A and B (all natural - no sharps or flats). Each note can be defined as representing a particular scale degree. Thus in the foregoing example based on C Major - the First Scale Degree is C. The Second Scale Degree is D. The Third scale degree is E and so on.

The D Major scale contains these seven notes: D E F# G A B and C#. Just as in the C Major scale - each of the seven notes in the D Major scale can be referred to by their scale degree. D = 1st - E = 2nd - F# = 3rd and so on.
So to transpose a melody from C Major to D Major you would look at each note in the melody (written in C Major) and determine its scale degree. Then to transpose that melody to D Major you would simply substitute the note in D Major that corresponded to the same scale degree.
For example if one of the notes in your C Major based melody was E (third scale degree of C Major) the corresponding note in D Major would be F# (third scale degree of D Major).

Using this systematic process you can transpose (convert) any melody from one key to any other key. The methodology is exactly the same regardless of the keys involved. I should point out that when transposing from a Major key - you will always transpose to another Major key to maintain the essence of the composition. You can't change a composition from Major to Minor or vice versa and still call it transposing.

If your melody contains an "accidental" (note from outside the key) you would modify the corresponding note in your transposition by applying the same value of deviation to the note matching the altered scale degree of the new key. In other words if your original melody was in C Major and one of the notes was F sharp you would "sharpen" the fourth degree note of whatever key you were transposing to. By "sharpen" I mean you would raise its pitch value by one semitone. So if the corresponding note was a flat (ie. B flat is 4th scale degree of the key of F Major) you would "sharpen" it by one half step (one semitone) to a natural (B Natural in the case of the B Flat in the key of F Major).

To help visualize how the Major Scales line up numerically with one another and to aid in your own transpositions you might find the chart below (from http://scheater5.blogspot.com) useful. Note this chart is for Major Scales only. You can find similar charts on line for Minor Scales.

Table of Major Scales

  • Your graph omits the keys with seven sharps and flats in them C# Major and Cb Major. – Neil Meyer Apr 5 '16 at 9:13
  • @NeilMeyer I suppose it does. I posted it as a visual example of the concept presented. C# Major contains the same exact notes as Db Major on equal tempered instruments such as keyboard or fretted instruments only with 7 sharps (hard to write in key signature instead of 5 flats? Even when played on violin C# is considered an enharmonic equivalent to Db (meaning you can't hear any difference). Similarly Cb Major is equivalent on piano, guitar etc. to B Major only instead of having to write seven flats you only have to use 5 sharps. Continued ... – Rockin Cowboy Apr 5 '16 at 18:19
  • @NeilMeyer ... While they technically exists, very few modern works feature 7 incidentals in the key signature when an enharmonic equivalent with only 5 can be used to specify the same melody. But you are technically correct. Good point. – Rockin Cowboy Apr 5 '16 at 18:20
  • @NeilMeyer - can't ever remember playing in Cb, or seeing music in that key. C#, being enharmonically the same as Db - I'd prefer Db so where's the point. – Tim Nov 6 '18 at 15:35
  • @Tim the fact that these kees have enharmonic keys or that they are rarely used does not stop them from existing. – Neil Meyer Nov 7 '18 at 8:01
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Following on from Rockin's excellent answer, it's apparent that KNOWING your keys and their respective signatures ('sharps and flats') is going to make the process much quicker to execute. On guitar, when using tunes that don't use open strings, the process won't use quite so much brain power. Just as a capo can help change key, you can do the same sort of thing. To move from, say, C to Eb, which is 3 semitones or a tone and a half, represented on guitar by 3 frets, merely play everything three frets higher than the original. To move to E (4 frets higher than C), shift everything up 4 frets. Provided there is enough room to manoeuvre, you could do the same plan downwards, e.g. C-Bb move all down 2 frets. No need to know what the notes are called, even!

On a slightly different tack, check out the NNS - Nashville Number System, which was conceived for chord charts as much as anything else. If your piece in C has a sequence C-G-F-C, then it translates to I-V-IV-I ( prefer Roman numerals) or 1-5-4-1. Knowing your chord families in other keys (vital!) means that the same sequence in E will be E-B-A-E. Simple!

  • Speaking purely personally, I've never used knowledge of keys/key signatures for this kind of thing - after a little experience of mucking around on the keyboard I always found it pretty easy to visually 'spot' the appropriate intervals on the keyboard from any root or tonic. I can't really see how thinking about key signatures could have sped things up (for me). The guitar is easier in some cases, but the limited range of each string and the kink in standard tuning make things more awkward again. Isomorphic keyboards are the instrument (interface?) of choice for easy transposition! – topo Reinstate Monica Apr 5 '16 at 10:14
  • @topomorto - funny, 'cos I work differently, in that I think C-E is a 3rd, so going into E, I need a 3rd of that, G, bearing in mind E has 4#, one being G#. So I probably work more from key sigs than physical intervals. – Tim Apr 5 '16 at 11:33
  • To me it would be just be a question of mentally moving my 'reference point' up four semitones and then 'playing the same thing'. Any more complex than that and I run out of brain power! – topo Reinstate Monica Apr 5 '16 at 11:58
  • @topomorto (and Tim by default) I have never been able to get my head around key signatures. It's as cumbersome for me as doing math with my fingers and toes. However I do like Tim's method of moving the guitar part up x number of frets. That will work if no open strings involved. FWIW - I posted this question to resurrect a poorly worded closed question that seemed to be asking about transposing for guitar and specifically mentioned open strings. – Rockin Cowboy Apr 5 '16 at 18:03
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You change the key to the interval you want to transpose. With this new key, you can just change the notes a number of spaces up or down and they will all be the same interval.

What do I mean by this? Let me further elaborate trough the use of an example. Let's say you want to transpose a passage that is in C major a Major third up. You use the key that is that interval ( A major third up from C --> E) and then just raises the notes three spaces on the staff.

This will conveniently make all the new notes the desired interval from the given passage.

So, for instance, you have this.

C Major

To transpose A major third in the new key you would now have this.

E Major

And now as you see all the new notes are a Major third up from the example. ( G -B, B - D#, D- F#, F - A, E- G#, C - E, A - C#, E - G#)

Finally just remember if there are any notes that are raised or lowered they still have to be reflected in your new passage for the intervals to be correct. In other words, don't discard sharps or flats.

  • It should be noted that this approach also requires that you change the key signature and works well for transcription if folks can read standard music notation on a 5 line staff. I personally prefer to read tablature and this approach will not work for that. I would also suspect that by the time someone has learned how to transcribe or read music in standard notation and write the proper key signature, they already know how to transpose. But your method is certainly valid and works perfectly for transcription. Good answer. – Rockin Cowboy Apr 5 '16 at 17:58

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