Student or Learner
Here is the definition of "to the tune of" from Longman English Dictionary:
5.to the tune of $1000/£2 million etc informal
used to emphasize how large an amount or number is
Canada is funding the programme to the tune of $30 million.
It is easy to understand but I wonder if this has something to do with literal meaning of "tune".
Is there any way to remember this easily?
not a teacher
Although "to the tune of an amount" sounds like an idiom to us, it seems to be quite an old usage that once had a broader application with meanings similar to "along the lines of" or "in accordance with", which also lingers in a phrase like "in tune with the times". There is a suggestion of a link to music and "harmony".
Here is a discussion of the phrase.
Why do we do things 'to the tune of' an amount of money?