Music at a kids party - am I missing the obvious?

[Workingonthemoon]

We've hired a hall for a kids party. No sound system.
For music last year we connected some computer speakers to my phone. That did not work - it was too quiet.
We don't have a stereo. We listen to music on the PC or our phones.
The music will have be youtube music on my phone. We don't have any CDs and have no way of ripping one.
So my question:

1. Is there a cheap but quite loud, relatively small stereo that connects to phones?

[Workingonthemoon]

Or an obvious alternative that I've not thought of?

[hungrytillater]

It's an external speaker that you need is it? Or a kind of docking station like you can get for ipods/ipads?

[Oswin]

B&m do cheap but big speakers that phones connect to.

[AvocadosAreGood]

Can’t you put a call out to your friends to use theirs? Someone must have something?

[chipsandpeas]

get a bluetooth speaker and play from you phone

[Dontfuckingsaycheese]

Ds got a rather fabulous Bluetooth speaker from the range. £20. It's too loud and has disco lights.

[Caulkheadupnorf]

Docking station or small speakers. I agree you can get them really cheaply. You can also put the phone in a bowl which amplifies the sound quite well.

Can you get a free trial for Apple Music?