Transposition

The Reasons for Transposition

To transpose music is simply to write it in a different key.  All the relationships between the notes remain the same in any key.  Notes that sound "as written" are not transposed away from the original key, because there is no need for transposition.   

There are a number of instruments that do not sound as written.  For these instruments, music is written in a different key from the original key, or concert key.  These transposing instruments include the B-flat Trumpet and Clarinet, as well as the Tenor and Soprano Saxophones in B-flat.  They read music in a key one whole step higher than the concert key.  If the concert key is B-flat major, their part is written in C major.  Instruments pitched in B-flat all sound a step below written.  The E-flat Alto Saxophone is transposed up a Major 6^th, and the Horn in F is transposed up a Perfect 5^th.  Memorize this adage:  “Transpose UP from the sounding pitch to the written pitch.”

To transpose tonal music from one key to another, identify the notes as scale degrees in the original key.  Then write the same scale degrees in the new key.  For example, if a tonic triad is outlined in the original key, a tonic triad must be outlined in the transposed key.  This is a much more musical method than treating each pitch individually and calculating an isolated interval.  It is also less prone to errors.