Ham. Do you think I am easier to be play'd on than a pipe? Call me what instrument you will, though you can fret me, you cannot play upon me.
A fret is the stop or key of a musical instrument, and consequently here is a play on words, and a double meaning. Hamlet says, though you can vex me, you cannot impose on me; though you can stop the instrument, you cannot play on it.
Scene 3. Page 216.
Ham. ... that his soul may be as damn'd and black
As hell, whereto it goes.
To the stories collected in the notes that illustrate Hamlet's shocking design of killing the king at his prayers, may be added one in Howel's Parley of the beasts, p. 91, and another related in Chetwind's Historical collections, p. 77.
Scene 4. Page 231.
Ham. ... a vice of kings.
"A low mimick of kings. The vice is the fool of a farce, from whence the modern punch is descended." Thus far Dr. Johnson. The first position in his note is questionable, the others erroneous. The vice belonged to the old moralities; and the modern Punch is most certainly not descended from him, but legitimately from a character well known in the theatres of ancient Rome. We have borrowed him from the Italian Polichinello. With respect to the former part of the note, Hamlet's expression may be quite literal. Thus in King Henry the Fifth, we have "this grace of kings." Afterwards indeed, Shakspeare, in his usual manner, recollecting the ambiguity of the term, takes up another simile, and makes Hamlet call his uncle a king of shreds and patches. See a former note in p. [287].