If we have Singers Nights (and I hope we will have) should the apostrophe go after the 's' or between the letters r and s? Indeed should we have that punctuation at all?

The first option means the night is possessed by the singers which surely is as it should be but if we assert that Singer's is the correct route to go down, that implies we only have one of 'em (the first to turn up?) which makes us so-ooo exclusive!

This has kept me awake at nights off and on, now for 4 decades!