Best thing to get

Hi
hope I’ve come to the right place as I have no idea about these things! My son is wanting to busk. He’s a dancer and has been out a few times and performed. The problem is we can’t work out how to get his music played loud enough. We’re wanting to get him a decent amp to play his backing tracks through but we have no idea where to start. Can anyone give us some pointers as to where we should start looking. Thanks for any help anyone can give