Professional contributing to a musical work by rewriting the composition for a medium of performance different from that for which the work was originally intended, or modifying the work for the same medium of performance, etc., such that the musical substance of the original composition remains essentially unchanged. For extensive modification that effectively results in the creation of a new musical work, see composer.

Equivalent to:

Equivalent	Details
arr	http://id.loc.gov/vocabulary/relators/arr