Music, much like sport, is seen by many working class people as a way to make some money, so not completely senseless. Art to a lesser extent.

Carpenters/joiners are a good half-way house, as they can provide both practical assistance to the community as well as selling collectibles/souvenirs or whatever.

The problem is the minute some of these people pick up skills or money, they leave the slums behind. The plumbers and electricians may make better money rigging up office blocks than from fitting out the slums.