The term 'Ceilidh Band' is another example; it used to be an Irish band, with anything up to a dozen or more people playing a mixture of squeezeboxes, fiddles, whistles and flutes, and perhaps the odd mandolin-banjo, often backed up by piano and a siple drum kit. Now the term is used by what used to be called 'Country Dance Bands' before the term became unfashionable. (Although the Country Dance Band was typically accordian/fidddle/guitar or something similar; now the 'ceilidh band' seems to be universally squeezebox led, and often has no fiddle, but saxophone, hurdy gurdy or some other instrument instead).
John Kelly.