When Cromwell came here (Dublin) he closed all the theatres and outlawed the musicians - and not just in Dublin.

Given that perception that people have, it always seems odd that one of the most successful music publishers of the 17th century, John Playford published much of his work during the Commonwealth (The first edition of the Dancing Master was published in 1651, two years after the execution of Charles I). That being the case, somehow I don't think music and dancing were actually outlawed. What Cromwell did do, I believe, was to stop the use of music in church services and to disband the cathederal choirs as this was considered ungodly and smacked of Popery. In fact I vaguely remember reading somewhere that Cromwell enjoyed social dancing. OTOH, the theatres definitely were closed and only reopened with the restoration of the Monarchy.

I think that Cromwell is often labelled with some of the excesses of his more extreme followers.