When you contribute a work on Musicalion you need to indicate whether it is an original composition or you are the arranger of a composition. This sometimes leads to confusion. What exactly is the difference?
There is a clear definition of a composition compared to an arrangement:
In classical music, a composition is the invention of a musical work, both in melody and in harmonic and formal structure. It may contain quotations from other compositions though. Other than that it must be clearly recognizable as an independent work. Therefore the arrangement of a folk song for mixed choir is not yet an independent composition.
An arrangement means that the original composition is musically edited. The arrangement corresponds to the original in melody and structure of movements but musical extensions or reductions are made. Even if only slight changes are made the piece is an arrangement. The folk song for mixed choir would thus be an arrangement.
When you copy a composition or an arrangement of a composition and in doing so only change the appearance of the score display this is not an arrangement and certainly not a composition as you did not change the musical content in any way.
Please also note: Not every arrangement automatically leads to a right to royalties from a copyright collecting society, because legally speaking, an arrangement is a transformation of a work that is itself creative. If the arrangement has sufficient creative depth, it can be registered as a new work with a collecting society. A new instrumentation, for example, is not to be regarded as an arrangement in the sense of a collecting society.
More information can be found here:
https://en.wikipedia.org/wiki/Musical_composition
https://en.wikipedia.org/wiki/Arrangement
