Hollywood musical not distinguished, initially, by repetition of notes (2,2,4)

'repetition of notes' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.

'hollywood musical not distinguished initially' is the wordplay.
'hollywood' becomes 'LA' (Hollywood is a neighbourhood of Los Angeles).
'musical' becomes 'lala' (I can't explain this - if you can you should believe this answer much more).
'initially' says to take the initial letters.
The initial letters of 'not distinguished' is 'nd'.
'la'+'lala'+'nd'='LA-LA-LAND'

'by' acts as a link.

Can you help me to learn more?