Guest,SB
The Cecil Sharp ticket page is :
https://uk.patronbase.com/_CecilSharpHouse/Productions/21/Performances




Ents24 seems to be used quite a bit by the busier bands.
I use their 'alerts'/'track' button and I don't get bothered with any extra spammy stuff.

get alerts for a venue e.g.
https://www.ents24.com/london-events/cecil-sharp-house 
or get alerts for an artist e.g.
https://www.ents24.com/uk/tour-dates/the-young-uns 
or see 'folk' in London
https://www.ents24.com/whatson/search/genre/celtic%2Cfolk/near/London/radius/10/order/date