If you choose to play online music, for whatever reason...I will not judge.
BUT
You really should NOT let your audience know about it.
If they know you CAN do it...
they will assume that you can play ANY song you can find, and you WILL play any song they request.
As Taso said, you lose control over the event.
So, you start off by defending yourself for the small crowd,
and then when it turns on you, you suddenly change your tune. (pun intended)
Look, stop worrying about your reputation here. We are not potential clients. We are also not perfect (except for Taso
If you had a bad night and want so advice....swallow your pride and listen to the advice being given.
You said it yourself from the beginning.
You had a choice and your chose poorly.
It happens.
Since it was a small crowd, at an event where they don't always stay...
you may not have been able to keep them there, even if you chose the reggae song.