Not having a pop at you but if people don't want to sing what the singing section are singing, sing something else.
It doesn't really matter if there's 3/4 songs & the easy City City going on at the same time, it's all noise. SS3 won't be able to hear 109/111 or 115/118 etc but we do our own thing, sometimes good sometimes piss poor.
If half a dozen fans in each block chant an easy one there's every chance others will join in. At least I'd like to think that would happen but, from the apathy of fans standing up as slowly as possible for the stand up for the champions chant I think it could be a lost cause.