Yes, John has it basically right.

Sibelius has its own built in "arranger'.

You can create a basic Fake Chart of Melody Line plus chordnames and then with one mouseclick you can have Sibelius make a full arrangement for a number of different types of ensembles, String Quartet, Brass Choir, Full Orchestra, Choir, smaller vocal singing group, etc. on the Classical side of things, and for the Bigband arranger, you can instantly make it into say a Basie arrangment or a Sammy Nestico or a Duke arrangement, etc.

Sibelius knows how to break that Melody and Chords out into parts for all the instruments involved in the chosen style and presents you with the full score of the work, all automatically. You can then just accept that, or you can go in there and Edit if you like.

And Sibelius does this so fast that it is always a bit disconcerting to me, even after all these years.


--Mac