Transposing a song - and the "key" to it all...

In fact, the key of F should have no flats.

No, F has one flat, a Bb.

Key of Bb does not have a D#, it has an Eb, as you've already figured out. :wink:

Bb-C-D-Eb-F-G-A

So, your song looks like it's in Bb to me.

Which means you are correct about transposing: capo on 3, play in G.

Check this out; enter your chords and it will automatically transpose to any key. I use it frequently with our praise band music:
http://www.logue.net/xp/

BTW, which Hillsong album is that one on?

I see slej got to this first, but I disagree - I think it is in F.

I'll deal with the practical part of your question first, then the theory.

When transposing with a capo, the rule is "capo up, chord down". If you have a Bb chord in the music, and you capo up one fret, you move the chord down one half step - you'd play A instead of Bb. Capo at the third fret, and you move the chord down three frets - from Bb to G.

So with capo on 3, you'd play G for the Bb, D for the F, C for the Eb, Em7 for the Gm7, Bm for the Dm, and so on.

Now for the theory part.... what key the progression is in.

First let's spell the chords so we can see what's really going on:

Bb/C = Bb-D-F-C = Bbadd9
F = F-A-C = F major (as does F/A and F/C)
Eb/F = Eb-G-Bb-F = Ebadd9
Eb/Bb = Eb-G-Bb = Eb
Gm7 = G-Bb-D-F
Bbmaj7 = Bb-D-F-A
Csus4 = C-F-G
C = C-E-G
A7 = A-C#-E-G (as does A/C#)
Dm = D-F-A
Bbm6/Db = Bb-Db-F-G = Bbm6
Bb/F = Bb-D-F = Db
Dm7 = D-F-A-C
Cm7 = C-Eb-G-Bb
B = B-D#-F#

Now if you list all the notes contained in those chords in order, you have:

A, Bb, C, C#/Db, D, D#/Eb, E, F, F#, G.

That's ten different notes, which means you can't be in a single key - major keys have seven notes, minor keys can have seven or nine (if you use the melodic minor). So you've got at least one modulation going on, and the song overall isn't in one key.

When that happens, the decision on which key signature to use depends on what the tonic or "key note" is. That's usually easier to see in melody - but we can look for clues in the chords. We look for "cadences", which are points of strong movement - the chord root is moving by a perfect fourth or fifth (there are other types of cadences, but these are the two most frequent). In many songs, the V-I cadence, called the "authentic" cadence is made stronger by using a dominant 7th chord... you've got only one dominant 7th, A7.

A7 wants to move to a D root, and it does, both times: to Dm, and then to Dm7.

Dm happens to be the relative minor of F.

In addition, the verse ends on F. But the chorus ends on Bb....

I'm guessing in performance, the song either "hangs" on the Bb at the end, or it's actually followed by a closing F chord.

The main reason I suspect a closing F is the genre - a IV-I cadence, called a "plagal" cadence, is so common in hymns it's also known as the "Amen" cadence.

Which would put your song in the key of F, with some modulation to Bb (and one "outside" chord where the roots move chromatically from C->B->Bb).

Which would put your song in the key of F with modulation to Bb and one "outside" chord.

Yeah, that's what I meant!

J/k; great information NoteBoat.

Interesting bit about the IV-I cadence, too. I see that often but never thought about it in context.

Wow. I mean...wow. Thanks, that really breaks it down.

P.S. When I said that the key of F has no flats, I was referring to the key signature of F, which has no flats, but rather one sharp, A#. Though I realise from a recent post that the key signature doesn't necessarily determine the key of the chord progression. Thanks for that transposer; I was just about writing my own, but I'll use that instead! :D

When I said that the key of F has no flats, I was referring to the key signature of F, which has no flats, but rather one sharp, A#.

No - the key signature of F has ONE FLAT, which is Bb. It doesn't have A#.

This illustrates nicely the point that keys, (unlike noisy children), should be heard and not seen.
I just had a listen to it here
http://uk.youtube.com/watch?v=HeP8R68p8uo
And the key is unmistakeably F major, (with some 'modal' flavouring, hence the Eb) ending, as NoteBoat says, with the appropriately named Amen Cadence.

When I said that the key of F has no flats, I was referring to the key signature of F, which has no flats, but rather one sharp, A#.

No - the key signature of F has ONE FLAT, which is Bb. It doesn't have A#.

Just to elaborate on that a little...

Key signatures have seven notes, one for each letter. Even though A# and Bb sound the same (in even temperament) and are played in the same place on the guitar, if you call it A# your scale looks like this:

F-G-A-A#-C-D-E-F

The letter B is missing.

If that note is called A#, you need to re-label all the other notes so there's one of each letter:

E#-Fx-Gx-A#-B#-Cx-Dx-E#

That's pretty awkward... four sharps, three double sharps. Much easier to write it with one flat:

F-G-A-Bb-C-D-E-F

E#-Fx-Gx-A#-B#-Cx-Dx-E#

:shock:

When I said that the key of F has no flats, I was referring to the key signature of F, which has no flats, but rather one sharp, A#.

No - the key signature of F has ONE FLAT, which is Bb. It doesn't have A#.

Perhaps this will help.
E#-Fx-Gx-A#-B#-Cx-Dx-E#

:shock:
x = ## :
E# - F## - G## - etc.......

Here's a table that I have found useful:

Major Relative Key I ii iii IV V vi vii°
Key Minor Signature 1 2 3 4 5 6 7
----------------------------------------------------------------
C major A minor C D E F G A B
G major E minor # G A B C D E F#
D major B minor ## D E F# G A B C#
A major F# minor ### A B C# D E F# G#
E major C# minor #### E F# G# A B C# D#
B major G# minor ##### B C# D# E F# G# A#
F# major D# minor ###### F# G# A# B C# D# E#
F major D minor b F G A Bb C D E
Bb major G minor bb Bb C D Eb F G A
Eb major C minor bbb Eb F G Ab Bb C D
Ab major F minor bbbb Ab Bb C Db Eb F G
Db major Bb minor bbbbb Db Eb F Gb Ab Bb C
Gb major Eb minor bbbbbb Gb Ab Bb Cb Db Eb F
----------------------------------------------------------------

In general, one prefers simpler key signatures. Bb (2 flats) is preferable to A# (10 sharps).

One can use either F# (6 sharps) or Gb (6 flats) for the same key. That's why there are 13 keys in the table, not 12.