You have to remember that ceili bands have a social function. It isn't like a night out with your mates at a session. Like all bands you have to learn tunes you may not particularly like, and play them in a pre-arranged order. Even worse, whilst a snare drum might sound like hell, and certainly doesat a session, druming is pretty much essential for a ceili band to fulfil its role.
If you play mostly for charity fundraisers or free for social events it can still be quite enjoyable and relaxed. If you want to play for weddings etc for cash, then you have to take it a bit more seriously (yawn). It is never as cramping as playing in a straight folk/trad band though (shudder : practice, arrangements etc. all that stuff that leeches the fun and spontaneity out of music)
IMHO the drummer is the most important member of a ceili band. The drummer sets the pace of the set, calls everyone to order, makes sure they all start together, sends out little hints when the tune is due to change or the set to end. Sometimes lets the dancers know when to move onto the next part of a tune (e.g. when to stop the waves in the waves of torey).
If something goes wrong through band organisation between the melody players e.g. a scratch, emergency band forgets the the tune order or someone changes too early, the drummer can keep things going for a bar or two before while the melody guys get their act together.
I can't listen to ceili bands for pleasure for any length of time because the drumming will drive me nuts. But in order to fullfill its social role a ceili band needs a strong drummer who knows what s/he is doing at its core.
The other main needs for a ceili band are: someone happy (and competent) to call the dances and ideally a strong box player to provide body. Some of these roles can be combined. Everyone else is an aslo-ran in the ceili band pecking order of importance. For those of you who play fiddle, pipes, flute, etc. Welcome to the world of the banjo player
All of the above holds true except on those occasions when, as is the case with everything, when it doesn't.
- chris