My thought was Sheffield.
But have a look at mister.red for the Mid West of England (& de Dwyrain Cymru).

If you prefer something more rural I can recommend Stroud. There are 3 Irish sessions a month one very Irish, a singaround that meets 3 times/mth, a weekly (& a monthly) folk club, a Ceilidh series (but we don't know what is happening next season), a monthly French Dance and a circle dance probably twice a month and depending how far you travel there are things in Gloucester, Cheltenham and the Forest of Dean. A Wassail in January, and a Folk Weekend in September. And the town is a nice size, for me anyway. It has a thriving Green Party and a reputation for being alternative. Two Saturday markets, one a renowned Farmers Market (one on Friday). A multiplex Cinema and a well presented Theatre run by the local amateur group that hosts touring productions, and two performance venues, Lansdown Hall and the Sub Rooms. Worth a recce before you make any decisions. We are friendly.

According to Wiki - Stroud the crime stats are good (all relative). And is on the main line to Lundun (innit?) something like an hourly service (2 hourly direct). And being on the edge of the Costwolds has some exceedingly pretty villages nearby.