Arranging is a making a creative variation of a musical work (special emphasis on the word “work”). However, not all variations constitute an arrangement; the so-called arrangement threshold is always assessed on a case-by-case basis.

When:

1. you make significant changes to the work, so that
2. the resulting work exceeds the so-called arrangement threshold, and
3. you intend to publish or present a work that has exceeded the arrangement threshold,

you need permission from the composer or publisher of the song if the work is still under copyright.

The arrangement threshold is likely to be exceeded when:

1. You add new musical elements to the work
2. You edit the work creatively and originally
3. You bring a clearly recognizable contribution to the work

What is not arranging?

As a rule, the arrangement threshold is not exceeded merely by:

1. reinstrumentation or orchestration (i.e., changing which instrument plays which part of the work)
2. simplification of the work
3. transposing the work, i.e. changing the pitch

For a work to exceed the arrangement threshold (which would result in a new work), clear creative input from the arranger is needed.