For a composer, it’s more than a question of taste or preference. If you’re relying on performers to take your musical ideas and turn them into a piece of music, you need to know how they’ll perform it, because that will have an influence on how your piece turns out.
Tunde Jegede describes the importance of choosing the right ‘personnel’.
Moving Away was composed from an oral perspective – meaning that it wasn’t written down for the performers to read. Instead Tunde talked to them, played with them, and described what he wanted the piece to express. Then it was down to the performers to get this right, each one bringing their own style and personality to the piece.
That means that Tunde himself had to know the styles and personalities of each of the performers, and use that knowledge to imagine (in his head) what the piece will sound like.
So choosing the right performers is a very important part of the composing process.