Transposing a piece of music is all about changing its key. It's not the most tricky part of music theory, but you do need to know about the different key signatures and modes to get it right. That is, if you're working with musical notation. If you've already got an audio file, you'll need a separate tool to transpose the track into the right key for vocalists. This article's got a detailed guide to transposing a song into a different key, covering both the theory and the practical.
1 Why transpose music?
The most obvious reason is to match the singer's vocal range. Not all singers can sing comfortably in the same key, so transposing a piece to a higher or lower key can make it more accessible.
Some keys are easier to play on certain instruments than others. For example, a piece in the key of C major may be easier for a beginning pianist to play than a piece in the key of F# major. Transposing to an easier key can make a piece more accessible.
Different instruments are tuned to different keys. For example, the Bb trumpet sounds a whole tone lower than it is written, so music written for the Bb trumpet should be transposed to match the tuning of the instrument. Guitarists tend to do better in keys with open chords on the fretboard, such as E, G, A, C, and D. Bb is not always popular with guitarists. C major is a bit boring for pianists, as many have told me.
You may simply want to change the overall feel of a song, and transposing can help. Say you want to take a happy pop tune and turn it into something darker. Or maybe you want to take something written for electric guitar and turn it into an acoustic campfire singalong. On an electric guitar, it's fairly easy to play chords high on the fretboard, and the amp will make sure they sound loud. On an acoustic, chords higher up the fretboard are not only harder to play, but they can also cause intonation issues and sound much quieter overall.
Ultimately, you may want to transpose a song because you want to, as a musical exercise. It will help you understand the theory better and improve your practical skills.
2 Let's start with the theory
So, transposition is the process of changing the key of a piece of music while keeping the same intervals between notes. This means that the overall structure and relationships between notes remain the same, but the pitch is shifted higher or lower. For example, if you transpose a piece from the key of C major to the key of G major, every note in the piece is shifted up a perfect fifth. The melody, harmony, and rhythm remain the same, but the piece is pitched higher.
Where to start? Let's look at the simplest case - you know the current key and you need to change it to another. Before transposing music, I hope you are already familiar with the basics of keys and scales. To transpose music, we need to know the interval - this is the distance between two notes. If you play each note on the piano in turn from left to right, you will get 12 tones that make up the chromatic scale:
C C#/Db D D#/Eb E F F#/Gb G G#/Ab A A#/Bb B
Since most software allows you to set intervals in semitones, you can calculate them manually. If you do not remember the intervals in notes, it is better to use a calculator.
After that, you need to select a program to change the key and below I suggest you consider two possible options.
3 Transpose music with AudioRetoucher in Windows
AudioRetoucher is designed for pitch shifting and time stretching, so it is well suited for transposing music in different formats. At the moment, we are interested in the ability to change the key of a song without changing the tempo. Since the last revision of this article, it has acquired support for new formats and significantly increased the speed of work.
Since the last revision of this article, it has acquired support for new formats and significantly increased the speed of work. Both lossy formats MP3, AAC and lossless formats - FLAC and WAV are supported. The disadvantages include a sampling frequency limit of 48000 Hz, probably due to the fact that higher frequencies cannot be processed in real time.
Having loaded an audio file, we can immediately move the Pitch slider by the number of semitones obtained from the calculator. The range is +/- 12 semitones with a step of 0.1 semitone. It is good that there is an option to pre-listen to the result and adjust it on the fly. This will allow us to adjust the interval if the result does not somehow fall within the specified key. In principle, with regular use, the result can be saved without saving, but immediately proceed to exercises.
4 Transposing song online with Transposr.com
There are a huge number of music processing services on the Internet, many of them are free, but they do not provide any details about the algorithms used, so you can only choose by trial and error.
I decided not to waste a lot of time and tried the first one from the search results - Transposr. The interface is very laconic and does not allow you to evaluate the quality on the fly or use fine tuning when working with off-key singing. The only plus is the ability to select the source and target keys, so you can do without a third-party calculator.
The service only works with MP3 files, which may require additional conversion of your songs. However, the result was obtained quickly, and we can move on to comparing the two competitors.
5 Comparison of transposition quality
When evaluating by ear, I immediately noticed the somewhat compressed sound of Transposr and clearly audible artifacts on transitions. Perhaps I am biased, so both processed files were loaded into the sound editor along with the original song. The screenshot clearly shows that my hearing did not fail me and artifacts are quite common. The web service algorithm is very far from commercial developments and I do not understand who its target audience is. Musicians can always use the transposition function in professional software, but for amateurs, the service's capabilities are very meager.
As for AudioRetoucher, it again demonstrated an excellent result, which is the result of 20 years of development. By ear, its result is close to Zynaptiq or Melodyne, which belong to a different price range.
6 Bottom line
Transposing music into another key is usually done using musical notation, and processing ready-made audio files can cause some difficulties. Most often, this is done to adapt the composition to a beginner student for rehearsals and exercises. However, sometimes it is necessary to change the key even for experienced performers. Some people think that there is no need to improve vocals, they should sound natural. But I don't think that listeners will agree with you. The end result is important to you, right? Then it is better to transpose and sound good than to resist and sound bad.
By understanding the basics of musical intervals, mastering transposing techniques and practicing regularly, you can master the skills of transposing music. No matter what software you use, you will always be able to choose the right settings. So grab your instrument, launch your notation program and start transposing! The world of music is waiting for you to discover new and exciting ways.