I ain't an English native speaker but I understand
(1) "This band is shit"
as negative (i.e. a very bad band), and
(2) "This band is the shit"
as positive (i.e. an extremely good band). I would convey, in French, the former as
(1) Ce groupe est nul
and the latter as
(2) Ce groupe est absurdement super.
A. What other ways exist to express the same meaning with (1) and (2) using words of similar register with shit. E.g.
(1) Ce groupe est merde
can convey the first meaning (i.e. the negative one)?
B. Are there any examples of phrases in French, that the lack of a definite article as above, completely changes the meaning of a sentence?