Flutist Joshua Smith on music and rhetoric...by Michael Gill...If you ever thought you were hearing voices in a Baroque melody or that the solo instrument in a given sonata was trying to explain something—to ask if you'd considered it this way and that, or given adequate consideration to the other — then you have an idea what Cleveland Orchestra principal flutist Joshua Smith has been thinking lately. "Part of the essence of Baroque style is that all these composers were so well versed in the concept of rhetoric…