So would it be possible to use blockchain to record that someone has done a task like, say, listened to a piece of music, and then they are sent tokens for completing it? Obviously you wouldn't be able to tell if they went out and let it play but just confirm the fact that they have played it through.
most certainly however your context may differ from others as to how the blockchain is used.
if the piece of music contained a certain note structure where there was 1 answer to the question, the answer could be hashed so as not to give away the text based answer. this answer would be published on the blockchain for all to see wet her it was correct or not.
your other method of reward would be a payment ledger which is what our beloved bitcoin is, its a DL of payment transactions.
not sure how you would implement it in your case to record and answer and issue a payment but i guess it could be possible.
My use is not so complex its just a ledger of users issued certificate.
I believe Lightning Network derived HTLC or hash time-locked contracts could do this, however it in itself is complex.
In a nutshell it involves 2-3 parties that have a hash of their own and each user adds their hash to complete the transaction based on another users hash. Within this contract there is a condition to be met, in your case it could be that their answer must equal the same hash and thus the correct hash answer releases a reward. Their is also a time component where if the user fails to meet the hash outcome within a specified time the reward is cancelled, or if someone cheats they are forfeited. Again this is just my gleaned and brief understanding.
I am still in the early days of LN and HTLC, but its something i am currently setting up. I am working on my own LN channel as i type.
Lots to learn and we are still in the early days of Bitcoin derived blockchain and DLT. Have fun.
