I've played in bands that did original material, cover bands, and now I do church gigs.
Original material bands are the easiest in terms of the demands on your playing technique - you learn a few sets of material that change slowly, everything stays in the same key, arrangements don't change very often (if at all), and you play the same stuff over and over. You do have to write (or at least someone in the band has to) new material from time to time (duh)
Cover bands are very similar skills wise. You probably have more material to learn, but the arrangements are even more set in stone - not too much changes, other than adding a couple tunes here, dropping a few there. If you have the skills for an original band, doing covers is a minor adjustment.
Church gigs are the most demanding thing I've done technically. Although the sets are short (20 to 30 minutes), the arrangements, the keys, the feel - everything changes from week to week (I play at multiple churches). I've literally played in all 12 keys. If I play the same part this week that I did last week on the same tune, it's probably wrong at least one, if not both of those times - you have to be very adaptable.
Original material bands are the easiest in terms of the demands on your playing technique - you learn a few sets of material that change slowly, everything stays in the same key, arrangements don't change very often (if at all), and you play the same stuff over and over. You do have to write (or at least someone in the band has to) new material from time to time (duh)
Cover bands are very similar skills wise. You probably have more material to learn, but the arrangements are even more set in stone - not too much changes, other than adding a couple tunes here, dropping a few there. If you have the skills for an original band, doing covers is a minor adjustment.
Church gigs are the most demanding thing I've done technically. Although the sets are short (20 to 30 minutes), the arrangements, the keys, the feel - everything changes from week to week (I play at multiple churches). I've literally played in all 12 keys. If I play the same part this week that I did last week on the same tune, it's probably wrong at least one, if not both of those times - you have to be very adaptable.

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