Transposer

Transposing chords from one key to another

Usage

To transpose chords, use transposer like this:

python transposer.py --from=F# --to=Eb input.txt

Input files

The input file should be a plain text file, but can contain any text - only lines starting with a vertical bar (|) will be transposed. On these lines, root notes must be in upper case while everything else should be in lower case.

Example

The contents of example.txt:

Rocking start, jazzy ending
| D | G A | Bbm7#11/Db |

Using transposer --from=D --to=E example.txt will produce the result

Result (D -> E):
Rocking start, jazzy ending
| E | A B | Cm7#11/D# |

Testing

Run unit tests using Python's doctest:

python -m doctest -v transposer.py