1.1 Transposition: changing keys  (Page 4/6)

The transposition you will use for one of these instruments will depend on what type of part you have in hand, and what instrument you would like to play that part. As with any instrumental part, be aware of the range of the instrument that you are writing for. If transposing the part up a perfect fifth results in a part that is too high to be comfortable, consider transposing the part down a perfect fourth instead.

To decide transpositions for transposing instruments

1. Ask: what type of part am I transposing and what type of part do I want? Do you have a C part and want to turn it into an F part? Do you want to turn a B flat part into a C part? Non-transposing parts are considered to be C parts. The written key signature has nothing to do with the type of part you have; only the part's transposition from concert pitch (C part) matters for this step.
2. Find the interval between the two types of part. For example, the difference between a C and a B flat part is one whole step. The difference between an E flat part and a B flat part is a perfect fifth.
3. Make sure you are transposing in the correct direction. If you have a C part and want it to become a B flat part, for example, you must transpose up one whole step. This may seem counterintuitive, but remember, you are basically compensating for the transposition that is "built into" the instrument . To compensate properly, always transpose by moving in the opposite direction from the change in the part names. To turn a B flat part into a C part (B flat to C = up one step), transpose the part down one whole step. To turn a B flat part into an E flat part (B flat to E flat = down a perfect fifth), transpose the part up a perfect fifth.
4. Do the correct transposition by interval , including changing the written key by the correct interval.

Your garage band would like to feature a solo by a friend who plays the alto sax. Your songwriter has written the solo as it sounds on his keyboard, so you have a C part. Alto sax is an E flat instrument; in other words, when he sees a C, he plays an E flat, the note a major sixth lower. To compensate for this, you must write the part a major sixth higher than your C part.

Your choral group is performing a piece that includes an optional instrumental solo for clarinet. You have no clarinet player, but one group member plays recorder, a C instrument. Since the part is written for a B flat instrument, it is written one whole step higher than it actually sounds. To write it for a C instrument, transpose it back down one whole step.

There's a march on your community orchestra's program, but the group doesn't have quite enough trombone players for a nice big march-type sound. You have extra French horn players, but they can't read bass clef C parts.

The trombone part is in C in bass clef; the horn players are used to reading parts in F in treble clef. Transpose the notes up a perfect fifth and write the new part in treble clef.