Holiday for jazz fans, hosting broadcasting mogul (11)
I believe the answer is:
billionaire
'holiday for jazz fans' is the definition.
I can't judge whether this defines the answer.
'hosting broadcasting mogul' is the wordplay.
'hosting' indicates putting letters inside (inserted letters are welcomed in or hosted).
'broadcasting' becomes 'on air' (broadcasting on the air).
'mogul' becomes 'billie' (I can't justify this - if you can you should believe this answer much more).
'onair' placed inside 'billie' is 'BILLIONAIRE'.
Can you help me to learn more?
(Another definition for billionaire that I've seen is " Very rich person".)