Answer:
Searching for 'electronic music schools' was the signal to target you with that ad.
Explanation:
Searching engines are a whole discipline right now. The power to offer what you probably like increase sales on internet.
When we search something, there's algorithms that save the key words you used. This is immediately is linked to the ad's algorithms to offer you some service or product related.
That's how Google, for example, offer you products related with your key words searched it before. The same happens with Spotify, algorithms save your key words (artist, specific songs, albums...) to offer you in the future a whole list related with your previous search.
