If you only do little clusters - three or four songs by one, and another, and then yet another - you lose the opportunity to think your way into the composer's mind, since, after all, most of these pieces are quite brief.
In fact, the element of play has an important role in my life, and I think that should be the case in the life of every artist. Our life is occupied with playing, whether we play an instrument or a role.
Toward the end of his life, one can sense that he was no longer thinking his way into the minds of others, causing them to speak on his behalf, but that he was now speaking for himself.
...in my lieder concerts, I always strove, when possible, to sing only the works of a single composer, so that the audience could be gradually drawn into a particular creative genius' way of thinking, and could follow him.
I believe Schubert had many different methods for familiarizing himself with a poem: reading it aloud and silently, always thinking up new ideas about it, first letting various things knock around inside his head, until he finally decides what to do.