The bands were marching bands whose members were mainly pre-teen girls, though the majorettes leading the bands with their twirling batons were always older girls, and the few boys who turned up preferred the snare drums as their instrument to the raucous kazoos. The bands in Ashington included the Melody Makers, the Gay Geordies (sic, gay still meant only happy in those more innocent times), and the Telstars, after the hit record by the Spotniks. At their height, these bands had up to one hundred members, practising three times a week, with some festival or competition to look forward to most weekends. Each band had an average of three double decker buses taking players and supporters to these events.
With a repertoire of jazz standards such as When the Saints go Marching in, these junior bands were loosely in the tradition of the marching colliery brass bands who turned out in force at gala days and miners' picnics.
You can see a preview of a 1960 film of the Ashington Melody Makers (with soundtrack) at the British Pathe site.