Conversation so far:
What was the Royal Academy of music?
The Royal Academy of Music in London, England, is the oldest conservatoire in the UK.
What did Edward German do with the Royal Academy of music?
He continued his studies of violin and organ, also beginning a more formal study of composition under Ebenezer Prout.
When did Edward German enter the Royal Academy of music as a sub-professor ?
1884

Question: For what reason?
Self-contained rewrite: For what reason did Edward German enter the Royal Academy of music as a sub-professor?