Was he the single greatest melodist that ever lived?

I'm currently learning all his sonatas, and the thing that amazes me the most about them, is that despite Mozart's habit of construcing his works from stock classical figurations and cliches, they are all tied together by one long, unbroken melody which could be sung by the human voice. Beethoven's sonatas, while commanding a much larger scope as far as form and harmony are concerned, do not have this quality of having an unbroken melody tying it all together, and non-sequiturs are not rare. It has been said that Mozart composed for one instrument, the human voice, and I can really hear why. Glenn Gould famously claimed him to be the easiest of the great composers to imitate, but I have yet to hear one of these convincing imitations. If anything, command of melody might the single most elusive part of composing.