Where is the accounting? Bands put together set lists and don’t run them by the owner of the establishment. There is no history of what was played, just the faulty memories of those in attendance.
CD jukeboxes aren’t paid out to the artists either.
Perhaps with the new internet jukeboxes you see in bars there is such accounting. But the bar owner can’t add a local album to the rotation as he once did.
The accounting is imperfect and complex, but it's not like there is none. They use a variety of monitoring, reporting, surveying, and statistical sampling.