Nobody should be singing, chanting, shouting, banging tables etc etc on public trains, for any reason, under any circumstances, ever. Football, stags, hens, drunks, random groups of bellowing oafs? Don't know, couldn't care any less if I tried, just give it a rest. They can bellow vacuous inanities at each other til their ears bleed in their own private space, but this is a part of the public realm in which everyone is effectively temporarily imprisoned.
Why should anyone else be forced to put up with their active choice to inflict an entirely elective and totally unnecessary projection of themselves onto those around them when they have zero interest and even less wish to endure it at painful volume for however long? It's a form of psychological assault.
The exact same thing applies, to a less extreme extent, to the use of speakerphone for... anything at all other than a 999 call when someone is having a heart attack or in labour and the caller needs to follow instructions with their hands free. In an ideal parallel universe it would be the social norm to seize the thing, thoroughly rearrange it with a handy sledgehammer and then return the shattered remnants to the transgressor.
This sort of thing is one of many reasons why getting people who enjoy at least a residual veneer of civilisation to use public transport is such a hard sell.