# Double Transposition and Key Recognition Help?



## Abracadabra

Strangely I couldn't find a "Music Theory" forum on this site, so I'm posting this question in "Beginners"

I'm transposing a popular folk song, "Danny Boy", from saxophone to trumpet. I'll be arranging accompaniment for this as well for some other instruments. In the meantime I have some truly "beginner" questions.

First off, I have the original score written for Saxophone. It's either in the key of D major, or B minor (in terms of the saxophone)

So that's my first question: *"How do you tell whether your in the major or minor key?"*

You can't tell from just the key signature alone. So what do you go by? The song ultimately ends on a D note does that mean it must be in D major instead of B minor?

Now I had to do a "double transposition". Allow me to explain.

This is the first transposition: (from an Eb alto sax to a Bb trumpet)










My sheet music program does this automatically. I just add the Bb trumpet, then copy and paste the score and it's all transposed. Really nice! 

However, there's a problem. The trumpet is a bit higher than I can play. So I needed to bring it down by 4 semitones. Fortunately my sheet music program handles that too so I end up with the following:










So now I have the trumpet in a range where I can play this piece.

Same question over again: *"What key am I in now Eb major, or C minor? (in terms of the trumpet)"*

Of course this should be the same as the answer to my first question. In other other words, if the original piece was a major piece than that's not going to change. Or if it was minor, than that wouldn't change either.

I'm thinking that I'm now in Eb major (at least in terms of the trumpet).

Now I need to write an accompaniment in concert key (which in this final case would be Db major I'm thinking)

Unless it's really Bb minor? But I'm pretty sure this is all major right?

So I need to write the accompaniment in Db major (concert key) right?

~~~~

I'm not confused, honest! :angel:

Just seriously unsure of what the heck I'm doing. :devil:


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## Lunasong

Abracadabra said:


> I'm thinking that I'm now in Eb major (at least in terms of the trumpet).
> 
> Now I need to write an accompaniment in concert key (which in this final case would be Db major I'm thinking)


You are correct on both counts. The easiest way for me to tell if a piece is major or minor (and what key it's in) is to what chord the tune wants to resolve.


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## Abracadabra

Lunasong said:


> You are correct on both counts. The easiest way for me to tell if a piece is major or minor (and what key it's in) is to what chord the tune wants to resolve.


So you'd basically need to listen to the music, and potentially even be able to play some chords, in order to determine the key?

I can see that working, but I was wondering if there was an easy way to tell just by looking at the score. I did look at the last note of the score which implied that it was the major key. (i.e. it ended on the root note of the major chord rather than on the root not of the minor chord). But I wasn't sure if that is a fail-proof method of making that determination.

In terms of actual dynamics (i.e. listening to things being played), after I had made this post I did start playing the Eb major scale on the trumpet, and then the C minor scale. It became clear at that time that the Eb major scale is going to work over this tune where the C minor scale does not fit at all. Still, this required hearing the piece played first, and then playing scales to compare with what the piece sounded like. So again, it wasn't a determination made purely from looking at the score. It required hearing the piece and then hearing some scales to compare it with.

So short of actually looking at the melody in the score and trying to figure out whether it's using notes from major or minor scales, there's really no simple way to know whether a piece is major or minor? Save for possibly also looking at how the piece ends to see what it's resolving to?

I'm just asking. I have no problem if this is the case. I just want to make sure. The reason being that I'm currently trying to figure out whether various pieces in method books I'm using are major or minor. I was hoping to just flip though the books marking each piece quickly as being major or minor. But now it appears that it won't be quite that simple. Unless a quick glance at the end of the piece to see what note(s) it finally resolves to is a dependable clue.


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## Lunasong

I see that PetrB has answered your question in this related post.


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## Abracadabra

Yes I see that. Thank you.


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