Prof. Mastusaka gave us a special lecture; The sounds in English and Japanese, at Senshu University yesterday.
I thoroughly enjoyed his wonderful lecture, and learned two things from it.
The first thing that I learned is the fact that a mastery of English sounds to the point of automatic control was not that difficult to be achieved as we might think. Prof. Matsusaka "eased" our concern in that respect by giving us some specific keys to clearing away our stumbling blocks.
The other thing is about English intonation per se. Intonation has some features; stress placement (nucleus), pitch accent, and the sound length. I was able to confirm that all these elements go in cahoot with each other and make a melody of English.