Principally where one learns about the home of trad? (3,7)
I believe the answer is:
new orleans
'home of trad?' is the definition.
(home of trad jazz)
'principally where one learns about' is the wordplay.
'principally' says to take the initial letters.
'about' is an anagram indicator.
The first letter of 'where' is 'w'.
'w'+'one'+'learns'='wonelearns'
'wonelearns' is an anagram of 'NEW ORLEANS'.
'the' is the link.
(Other definitions for new orleans that I've seen before include "port city in the south" , "City of Louisiana" , "Devastated city" , "US city" .)