Giving a good connotation to seemingly negative words is an old practice. To point where a word like 'terrific' no longer even holds a negative connotation... Even a word like "funky" is rarely used to describe a bad smell nowadays.
In Jazz, this practice has roots in the early days of the genre, with the development of "Jive Talk"... Even slang words that we consider to be used contemporaneously can be traced back to those "old" jazz days. See here for a glossary of Jive words that includes, 'bad,' 'the bomb,' 'kill,' etc. (All used to describe good things.)
What makes jazz nasty or disgusting? This is a good thing, right?
One of the points of slang in general is to create a sort of exclusivity. In this case in order to separate the "hep cats" from the "crumbs," the words 'nasty' and 'disgusting' are used to describe a piece of music and/or a performance that is excellent, well-crafted, and/or noteworthy. So yes, those seemingly negative words are a good thing and used as compliments in this case.
Also, there is no distinction between the two words as far as the quality of the compliment; in the sense that if a piece of music and/or a performance is at certain level then it can be described as 'nasty' but, if a piece of music and/or a performance is at this other, higher level then it can be described as 'disgusting.' Either word gives essentially the same compliment. If it can be argued that one holds a certain level of connotative quality over the other, then that argument can still be subject to invalidity over time and/or as it applies to some other 'in-group' that uses those terms differently.