Originally Posted by SonicAlchemist
the traditional approach to composition, as taught classically, is to not compose at an instrument at all. Everything done inside the imagination, pencil + paper with years of training. the point of this is to avoid the observation of this thread. otherwise we are not hearing the pure composer, we are hearing the composer through a filter of their skills on that instrument, which cannot help but unnecessarily limit their music.
one of my composition teachers was a concert pianist who soloed internationally with the Grieg and Schumann concertos, had studied at Julliard, etc. . . and he refused to compose at the piano because of how it would inevitably limit his writing to what he was capable of playing, and/or what he had spent time playing. that has stuck with me as profound over the years.
I don't find this argument very compelling. If a composer has an active imagination, then using an instrument as an aid is likely to only increase his creativity. If ideas come to him that are beyond his capabilities on the instrument, that's no big deal. That's normal and expected. He uses the instrument merely as a jumping off point and then writes what he knows someone else will be able to play. Writing purely in your head is one method. I've done it before. It can produce fine results. However, it's unclear to me that that method is better at freeing us from our "stuck in the rut" tendencies. It might even force us to rely even more on what we know works, especially in multi-part pieces, as we can't confirm what we think we're hearing in our head. For me it's usually by experimenting on an instrument that I discover new things. I don't know, telling a composer not to use an instrument is kinda like telling a painter not to sketch things out before putting paint to canvas.