Transposing Music
Source: Kids Music Theory
What Is Transposing Music?
That is a big word, but it has quite an easy explanation. Transposing Music means to change the key the written music. You can transpose either on paper (or manually), on on the fly by changing the key by playing by ear.
An Example:
As an example, in listening to some songs you will notice that after a few verses the artist will “shift-gears” so as to speak, and play the same song, or sing it, in a different key. This is called “Artist’s License” which means they can do whatever they want to do because it’s their song or their arrangement. 
Well kinda. But really what they are trying to to do is get a certain sound from the song. This can be much like a painter painting on canvas. They hear it in their head and they want to find the best way to produce that sound that they hear.
Another Example:
Let’s take the example of a Bluegrass Band. This band usually consists of a Bass, a Guitar, a Violin, a Banjo and a Mandolin. Now the entire group has to play together on the same song and of course in the same key or it would be painful to listen to.
The Violin and the Mandolin are tuned exactly the same so they are already in sync. They are usually the happiest playing in either the key of D Major or the Key of A Major and sometimes in C and G.
The guitar player will be happiest playing in the keys of C and G major. Oops, that does not match the violin or mandolin. The answer is to capo the 2nd fret making the C a D and the G and A. Problem solved.
Okay now the Banjo. Who cares about the Banjo? Well the banjo player does. He is happiest playing in A, G or D or sometimes C. They also use alternate tunings and can capo to play easily in A, D and G. Another problem solved.
The Bass player can usually play in any reasonable key so he is just along for the ride.
Ultimate Kids Guitar Lessons Tip: The above example indicates what is most common for this sort of band. They of course play songs in a variety of keys, but I would bet that most groups stay in G, D and A 80% of the time.
Who Chooses The Key A Song Will Be Written?
As indicated above the original score or music composition is often changed by musicians to include more fill-in notes, chords and yes, key changes to fit their needs or their musical abilities and/or to meet the restrictions of their instruments.
I have written and arranged next week’s song, The Wheels of the Bus, in the key of G Major. Now I have no idea what key that song was originally written, because it varies by each composer. He or she may want to have the song either higher or lower because it fits their vocal range better.
Or a composer may write and play a song for the piano, or violin or some other instrument. Another reason may be there will be various instruments playing the song and you have to choose some common ground where all the musicians are comfortable playing in that particular key – as in the example of the bluegrass band above.
As for the guitar, it is the easiest to play in mostly keys with sharps, like C (all naturals), G (1 sharp), D (2 sharps) and so on. Okay I got slightly off track here. Anyway, I selected the Key of G Major for that song because it was comfortable to play it there. Good enough reason, right?
In the next section on Music Transposition, we will look at the most common keys that are shifted to and why. Also we will look at the actual process of Transposition.
Tags: changing keys, how to transpose music, music transposition, using a capo to change keys, what is transposing music
