SA bands in London have definitely seen a decline over the past years, linked with the changing population of inner city areas. Throughout the history of the Salvation Army, much of the work originated at the lower end of society, in the poorest areas. As converts were made, there was often a change in lifestyle which in many cases led to a move to better housing and employment, frequently in a different area of town. Thus many of the Army's musicians came to move away from the first centres, and even though there may still have been an SA presence the numbers in the band and songsters may well have declined.
To some extent that is still happening, and is often affected by the change in the ethnic mix of an area. Corps such as Cambridge Heath and Chalk Farm, with long banding histories, have seen many changes over the years; both Corps, as far as being worship centres is concerned, are thriving, with active community programmes, although the sections are smaller than before and new people coming in may have little interest in banding. You also have places such as Upper Norwood and Wood Green, whose sections have also declined.
You may also have the situation where, if people are going to have to travel in order to attend their place of worship, they may be attracted by the larger centres, such as Regent Hall, where there are active programmes for children and youth as well as for adults wishing to play in the band.
