Mini-episode: Why does the word 'sonata' keep turning up?

If you're exploring classical music, you'll bump into the term 'sonata' everywhere - piano sonatas, violin sonatas, trio sonatas… even sonata-form. This mini-episode untangles the many meanings of this surprisingly variable word, from its simple origins in Italian to its complex modern uses. And suggests perhaps why composers keep using it when they want you to really listen.