Clue: Stuff and nonsense noted? (4)
Answer: JAZZ
Explanation: Definition: Stuff
Two non-musical definitions of jazz from Chambers: "to have sexual intercourse (with)", which is also a slang meaning of "stuff"; and "insincere or lying talk, nonsense (slang, esp. US)", with "noted" to hint at the musical meaning. *Or maybe the "stuff" is, more innocently, as in "all that jazz".