I'm with
@Sagax on this. Lets use the logic.
If I am producing 500 tourism (including % cards) a turn then that is 750 tourism with open border and trade route to a single civ but I have 7 civs and so that is 5250 tourism per turn I am generating on a standard size map. As I understand it Rock bands do not produce over 5K tourism and have to travel to different venues so the turns in between playing create no tourism from rock bands.
However it is not as bleak as it sounds. A rock band only affects the civ you are playing in (unless you have the 10 tile promotion) so if you play to the player with the leading domestic culture against you then you are concentrating say 3.6 K (roughly the max?) of tourism on one civ. As you need 1800 tourism to get a point off a civ (and reduce their domestic by 1) a single concert will in essence boost you 4 points toward victory which is not a small thing.
However it is not that wonderful because that is seemingly the max, and to get the max you need to play the right venues and I am not sure if wonders will add 1K tourism too this as a parameter suggests. The key things are
1. If you are maybe 20 points away from a CV and getting closer then this will speed up your victory which to be honest is likely inevitable and the choice is yours to use them or not. It is an option to finish your CV without thrashing the last few turns.
2. If you are 100 points away from a CV then rock bands get progressively more expensive (80 faith per band) and will eventually outpace your faith output.
3. If another civ is producing 200 culture per turn then they are increasing by 2 points and you are say reducing by 2 points then you are slowed to 2 points per victory each concert. However, if the civ gets to 300 culture per turn then you are treading water, nothing more and you need to reduce that civs culture.... this can be done by wiping out the culture CS's and stealing works or pure invasion but it is not a done deal.
4. If you play at a target other than your highest domestic tourist opposition then you are giving yourself maybe up to 2 points toward victory.
So my take on rock bands is if you play a fast CV you will not need them as CV's are now roughly sped up somewhere between 5-10% due to a different governments modifier change. If you are not playing a fast CV (as many do not) then you can use bands as much as you want and speed yoru CV victory up or just play them at different civs because it is fun... and that is the main reason you are playing.
Are they OP?.... on prince yes, on deity a small bit if used right.
Will Firaxis twek their chances of success?.... well they seem to be much more successful now than in the livefeed so maybe they have temp buffed them during release and will be intentionally nerfed later for better gameplay.
Last night Kongo sent multiple Rock Bands to perform in my lands. I was pleasantly surprised. I wonder if it had anything to do with me being about 30 turns away from a CV?
Nope, the only defense Kongo gets against your victory is getting more culture and a rock band only produces tourism... So Kongo is trying to beat you to a CV or is badly programmed to think it can stop you.