to be danced to

[keannu]

I think "to dance to" also works here, but why was "to be danced to" used as a passive tense hard to understand?

ex)Because classical music today has largely become something we listen to in concert or on recordings, it is easy to forget the essential role it once played as a part of daily life....As time passed, however dance music gradually became more abstract and sophisticated and eventually left its original real-world function behind. Put simply, the minuet, which was originally designed to be danced to, ultimately became something to listen to, and the switch transformed both content and form.

 

[Tdol]

To dance to works, but I really don't see anything hard to understand about the passive.

 

[keannu]

Then, what do you think is the active voice for it? It seems hard to convert this to an active voice, so it just seems to have its active voice meaning implied.
ex)Put simply, the minuet, which was originally designed to be danced to,(= which they designed to dance to?)

 

[Tdol]

You don't need to convert- just replace:

the minuet, which was originally designed ​

to be danced to

the minuet, which was originally designed ​

to dance to

 

[BobK]

:up: ...to say nothing of the informal but understandable 'This song is very danceable-to'.

b

 

[5jj]

Then, what do you think is the active voice for it?

It seems to me that you are trying to analyse language too logically. Sometimes one just has to accept that certain things in a language just are.