Mark,  I don't know what link you are referring to... if you click on the "Mummers" link, then click on the additional "learn more about" resource links, you should be able to get a feel for what the Mummers are all about.

Basically, the tradition is about celebration, especially the New Year, but the Mummers String Bands perform all year long at special events and parades.  

I invite you to access the resource links to "...learn more about the Mummers" -- you should find enough on the history along with photos, music clips and videos to give you a feel for what they are all about and their unique sound.

While there are recordings and photos available to access, they really have to be experienced live -- preferrably during a parade while they are marching, strutting and playing (they put out a lot of sound as they go by) down the street.  Once you see and hear them, you can never confuse them with anything else.